text: /*
   * apply.c
   *
   * Copyright (C) Linus Torvalds, 2005
   *
   * This applies patches on top of some (arbitrary) version of the SCM.
   *
   */
  
  #include "cache.h"
  #include "config.h"
  #include "object-store.h"
  #include "blob.h"
  #include "delta.h"
  #include "diff.h"
  #include "dir.h"
  #include "xdiff-interface.h"
  #include "ll-merge.h"
  #include "lockfile.h"
  #include "parse-options.h"
  #include "quote.h"
  #include "rerere.h"
  #include "apply.h"
  
  struct gitdiff_data {
  	struct strbuf *root;
  	int linenr;
  	int p_value;
  };
  
  static void git_apply_config(void)
  {
  	git_config_get_string_const("apply.whitespace", &apply_default_whitespace);
  	git_config_get_string_const("apply.ignorewhitespace", &apply_default_ignorewhitespace);
  	git_config(git_default_config, NULL);
  }
  
  static int parse_whitespace_option(struct apply_state *state, const char *option)
  {
  	if (!option) {
  		state->ws_error_action = warn_on_ws_error;
  		return 0;
  	}
  	if (!strcmp(option, "warn")) {
  		state->ws_error_action = warn_on_ws_error;
  		return 0;
  	}
  	if (!strcmp(option, "nowarn")) {
  		state->ws_error_action = nowarn_ws_error;
  		return 0;
  	}
  	if (!strcmp(option, "error")) {
  		state->ws_error_action = die_on_ws_error;
  		return 0;
  	}
  	if (!strcmp(option, "error-all")) {
  		state->ws_error_action = die_on_ws_error;
  		state->squelch_whitespace_errors = 0;
  		return 0;
  	}
  	if (!strcmp(option, "strip") || !strcmp(option, "fix")) {
  		state->ws_error_action = correct_ws_error;
  		return 0;
  	}
  	/*
  	 * Please update $__git_whitespacelist in git-completion.bash
  	 * when you add new options.
  	 */
  	return error(_("unrecognized whitespace option '%s'"), option);
  }
  
  static int parse_ignorewhitespace_option(struct apply_state *state,
  						 const char *option)
  {
  	if (!option || !strcmp(option, "no") ||
  	    !strcmp(option, "false") || !strcmp(option, "never") ||
  	    !strcmp(option, "none")) {
  		state->ws_ignore_action = ignore_ws_none;
  		return 0;
  	}
  	if (!strcmp(option, "change")) {
  		state->ws_ignore_action = ignore_ws_change;
  		return 0;
  	}
  	return error(_("unrecognized whitespace ignore option '%s'"), option);
  }
  
  int init_apply_state(struct apply_state *state,
  		     struct repository *repo,
  		     const char *prefix)
  {
  	memset(state, 0, sizeof(*state));
  	state->prefix = prefix;
  	state->repo = repo;
  	state->apply = 1;
  	state->line_termination = '\n';
  	state->p_value = 1;
  	state->p_context = UINT_MAX;
  	state->squelch_whitespace_errors = 5;
  	state->ws_error_action = warn_on_ws_error;
  	state->ws_ignore_action = ignore_ws_none;
  	state->linenr = 1;
  	string_list_init(&state->fn_table, 0);
  	string_list_init(&state->limit_by_name, 0);
  	string_list_init(&state->symlink_changes, 0);
  	strbuf_init(&state->root, 0);
  
  	git_apply_config();
  	if (apply_default_whitespace && parse_whitespace_option(state, apply_default_whitespace))
  		return -1;
  	if (apply_default_ignorewhitespace && parse_ignorewhitespace_option(state, apply_default_ignorewhitespace))
  		return -1;
  	return 0;
  }
  
  void clear_apply_state(struct apply_state *state)
  {
  	string_list_clear(&state->limit_by_name, 0);
  	string_list_clear(&state->symlink_changes, 0);
  	strbuf_release(&state->root);
  
  	/* &state->fn_table is cleared at the end of apply_patch() */
  }
  
  static void mute_routine(const char *msg, va_list params)
  {
  	/* do nothing */
  }
  
  int check_apply_state(struct apply_state *state, int force_apply)
  {
  	int is_not_gitdir = !startup_info->have_repository;
  
  	if (state->apply_with_reject && state->threeway)
  		return error(_("--reject and --3way cannot be used together."));
  	if (state->cached && state->threeway)
  		return error(_("--cached and --3way cannot be used together."));
  	if (state->threeway) {
  		if (is_not_gitdir)
  			return error(_("--3way outside a repository"));
  		state->check_index = 1;
  	}
  	if (state->apply_with_reject) {
  		state->apply = 1;
  		if (state->apply_verbosity == verbosity_normal)
  			state->apply_verbosity = verbosity_verbose;
  	}
  	if (!force_apply && (state->diffstat || state->numstat || state->summary || state->check || state->fake_ancestor))
  		state->apply = 0;
  	if (state->check_index && is_not_gitdir)
  		return error(_("--index outside a repository"));
  	if (state->cached) {
  		if (is_not_gitdir)
  			return error(_("--cached outside a repository"));
  		state->check_index = 1;
  	}
  	if (state->ita_only && (state->check_index || is_not_gitdir))
  		state->ita_only = 0;
  	if (state->check_index)
  		state->unsafe_paths = 0;
  
  	if (state->apply_verbosity <= verbosity_silent) {
  		state->saved_error_routine = get_error_routine();
  		state->saved_warn_routine = get_warn_routine();
  		set_error_routine(mute_routine);
  		set_warn_routine(mute_routine);
  	}
  
  	return 0;
  }
  
  static void set_default_whitespace_mode(struct apply_state *state)
  {
  	if (!state->whitespace_option && !apply_default_whitespace)
  		state->ws_error_action = (state->apply ? warn_on_ws_error : nowarn_ws_error);
  }
  
  /*
   * This represents one "hunk" from a patch, starting with
   * "@@ -oldpos,oldlines +newpos,newlines @@" marker.  The
   * patch text is pointed at by patch, and its byte length
   * is stored in size.  leading and trailing are the number
   * of context lines.
   */
  struct fragment {
  	unsigned long leading, trailing;
  	unsigned long oldpos, oldlines;
  	unsigned long newpos, newlines;
  	/*
  	 * 'patch' is usually borrowed from buf in apply_patch(),
  	 * but some codepaths store an allocated buffer.
  	 */
  	const char *patch;
  	unsigned free_patch:1,
  		rejected:1;
  	int size;
  	int linenr;
  	struct fragment *next;
  };
  
  /*
   * When dealing with a binary patch, we reuse "leading" field
   * to store the type of the binary hunk, either deflated "delta"
   * or deflated "literal".
   */
  #define binary_patch_method leading
  #define BINARY_DELTA_DEFLATED	1
  #define BINARY_LITERAL_DEFLATED 2
  
  static void free_fragment_list(struct fragment *list)
  {
  	while (list) {
  		struct fragment *next = list->next;
  		if (list->free_patch)
  			free((char *)list->patch);
  		free(list);
  		list = next;
  	}
  }
  
  static void free_patch(struct patch *patch)
  {
  	free_fragment_list(patch->fragments);
  	free(patch->def_name);
  	free(patch->old_name);
  	free(patch->new_name);
  	free(patch->result);
  	free(patch);
  }
  
  static void free_patch_list(struct patch *list)
  {
  	while (list) {
  		struct patch *next = list->next;
  		free_patch(list);
  		list = next;
  	}
  }
  
  /*
   * A line in a file, len-bytes long (includes the terminating LF,
   * except for an incomplete line at the end if the file ends with
   * one), and its contents hashes to 'hash'.
   */
  struct line {
  	size_t len;
  	unsigned hash : 24;
  	unsigned flag : 8;
  #define LINE_COMMON     1
  #define LINE_PATCHED	2
  };
  
  /*
   * This represents a "file", which is an array of "lines".
   */
  struct image {
  	char *buf;
  	size_t len;
  	size_t nr;
  	size_t alloc;
  	struct line *line_allocated;
  	struct line *line;
  };
  
  static uint32_t hash_line(const char *cp, size_t len)
  {
  	size_t i;
  	uint32_t h;
  	for (i = 0, h = 0; i < len; i++) {
  		if (!isspace(cp[i])) {
  			h = h * 3 + (cp[i] & 0xff);
  		}
  	}
  	return h;
  }
  
  /*
   * Compare lines s1 of length n1 and s2 of length n2, ignoring
   * whitespace difference. Returns 1 if they match, 0 otherwise
   */
  static int fuzzy_matchlines(const char *s1, size_t n1,
  			    const char *s2, size_t n2)
  {
  	const char *end1 = s1 + n1;
  	const char *end2 = s2 + n2;
  
  	/* ignore line endings */
  	while (s1 < end1 && (end1[-1] == '\r' || end1[-1] == '\n'))
  		end1--;
  	while (s2 < end2 && (end2[-1] == '\r' || end2[-1] == '\n'))
  		end2--;
  
  	while (s1 < end1 && s2 < end2) {
  		if (isspace(*s1)) {
  			/*
  			 * Skip whitespace. We check on both buffers
  			 * because we don't want "a b" to match "ab".
  			 */
  			if (!isspace(*s2))
  				return 0;
  			while (s1 < end1 && isspace(*s1))
  				s1++;
  			while (s2 < end2 && isspace(*s2))
  				s2++;
  		} else if (*s1++ != *s2++)
  			return 0;
  	}
  
  	/* If we reached the end on one side only, lines don't match. */
  	return s1 == end1 && s2 == end2;
  }
  
  static void add_line_info(struct image *img, const char *bol, size_t len, unsigned flag)
  {
  	ALLOC_GROW(img->line_allocated, img->nr + 1, img->alloc);
  	img->line_allocated[img->nr].len = len;
  	img->line_allocated[img->nr].hash = hash_line(bol, len);
  	img->line_allocated[img->nr].flag = flag;
  	img->nr++;
  }
  
  /*
   * "buf" has the file contents to be patched (read from various sources).
   * attach it to "image" and add line-based index to it.
   * "image" now owns the "buf".
   */
  static void prepare_image(struct image *image, char *buf, size_t len,
  			  int prepare_linetable)
  {
  	const char *cp, *ep;
  
  	memset(image, 0, sizeof(*image));
  	image->buf = buf;
  	image->len = len;
  
  	if (!prepare_linetable)
  		return;
  
  	ep = image->buf + image->len;
  	cp = image->buf;
  	while (cp < ep) {
  		const char *next;
  		for (next = cp; next < ep && *next != '\n'; next++)
  			;
  		if (next < ep)
  			next++;
  		add_line_info(image, cp, next - cp, 0);
  		cp = next;
  	}
  	image->line = image->line_allocated;
  }
  
  static void clear_image(struct image *image)
  {
  	free(image->buf);
  	free(image->line_allocated);
  	memset(image, 0, sizeof(*image));
  }
  
  /* fmt must contain _one_ %s and no other substitution */
  static void say_patch_name(FILE *output, const char *fmt, struct patch *patch)
  {
  	struct strbuf sb = STRBUF_INIT;
  
  	if (patch->old_name && patch->new_name &&
  	    strcmp(patch->old_name, patch->new_name)) {
  		quote_c_style(patch->old_name, &sb, NULL, 0);
  		strbuf_addstr(&sb, " => ");
  		quote_c_style(patch->new_name, &sb, NULL, 0);
  	} else {
  		const char *n = patch->new_name;
  		if (!n)
  			n = patch->old_name;
  		quote_c_style(n, &sb, NULL, 0);
  	}
  	fprintf(output, fmt, sb.buf);
  	fputc('\n', output);
  	strbuf_release(&sb);
  }
  
  #define SLOP (16)
  
  static int read_patch_file(struct strbuf *sb, int fd)
  {
  	if (strbuf_read(sb, fd, 0) < 0)
  		return error_errno("git apply: failed to read");
  
  	/*
  	 * Make sure that we have some slop in the buffer
  	 * so that we can do speculative "memcmp" etc, and
  	 * see to it that it is NUL-filled.
  	 */
  	strbuf_grow(sb, SLOP);
  	memset(sb->buf + sb->len, 0, SLOP);
  	return 0;
  }
  
  static unsigned long linelen(const char *buffer, unsigned long size)
  {
  	unsigned long len = 0;
  	while (size--) {
  		len++;
  		if (*buffer++ == '\n')
  			break;
  	}
  	return len;
  }
  
  static int is_dev_null(const char *str)
  {
  	return skip_prefix(str, "/dev/null", &str) && isspace(*str);
  }
  
  #define TERM_SPACE	1
  #define TERM_TAB	2
  
  static int name_terminate(int c, int terminate)
  {
  	if (c == ' ' && !(terminate & TERM_SPACE))
  		return 0;
  	if (c == '\t' && !(terminate & TERM_TAB))
  		return 0;
  
  	return 1;
  }
  
  /* remove double slashes to make --index work with such filenames */
  static char *squash_slash(char *name)
  {
  	int i = 0, j = 0;
  
  	if (!name)
  		return NULL;
  
  	while (name[i]) {
  		if ((name[j++] = name[i++]) == '/')
  			while (name[i] == '/')
  				i++;
  	}
  	name[j] = '\0';
  	return name;
  }
  
  static char *find_name_gnu(struct strbuf *root,
  			   const char *line,
  			   int p_value)
  {
  	struct strbuf name = STRBUF_INIT;
  	char *cp;
  
  	/*
  	 * Proposed "new-style" GNU patch/diff format; see
  	 * https://public-inbox.org/git/7vll0wvb2a.fsf@assigned-by-dhcp.cox.net/
  	 */
  	if (unquote_c_style(&name, line, NULL)) {
  		strbuf_release(&name);
  		return NULL;
  	}
  
  	for (cp = name.buf; p_value; p_value--) {
  		cp = strchr(cp, '/');
  		if (!cp) {
  			strbuf_release(&name);
  			return NULL;
  		}
  		cp++;
  	}
  
  	strbuf_remove(&name, 0, cp - name.buf);
  	if (root->len)
  		strbuf_insert(&name, 0, root->buf, root->len);
  	return squash_slash(strbuf_detach(&name, NULL));
  }
  
  static size_t sane_tz_len(const char *line, size_t len)
  {
  	const char *tz, *p;
  
  	if (len < strlen(" +0500") || line[len-strlen(" +0500")] != ' ')
  		return 0;
  	tz = line + len - strlen(" +0500");
  
  	if (tz[1] != '+' && tz[1] != '-')
  		return 0;
  
  	for (p = tz + 2; p != line + len; p++)
  		if (!isdigit(*p))
  			return 0;
  
  	return line + len - tz;
  }
  
  static size_t tz_with_colon_len(const char *line, size_t len)
  {
  	const char *tz, *p;
  
  	if (len < strlen(" +08:00") || line[len - strlen(":00")] != ':')
  		return 0;
  	tz = line + len - strlen(" +08:00");
  
  	if (tz[0] != ' ' || (tz[1] != '+' && tz[1] != '-'))
  		return 0;
  	p = tz + 2;
  	if (!isdigit(*p++) || !isdigit(*p++) || *p++ != ':' ||
  	    !isdigit(*p++) || !isdigit(*p++))
  		return 0;
  
  	return line + len - tz;
  }
  
  static size_t date_len(const char *line, size_t len)
  {
  	const char *date, *p;
  
  	if (len < strlen("72-02-05") || line[len-strlen("-05")] != '-')
  		return 0;
  	p = date = line + len - strlen("72-02-05");
  
  	if (!isdigit(*p++) || !isdigit(*p++) || *p++ != '-' ||
  	    !isdigit(*p++) || !isdigit(*p++) || *p++ != '-' ||
  	    !isdigit(*p++) || !isdigit(*p++))	/* Not a date. */
  		return 0;
  
  	if (date - line >= strlen("19") &&
  	    isdigit(date[-1]) && isdigit(date[-2]))	/* 4-digit year */
  		date -= strlen("19");
  
  	return line + len - date;
  }
  
  static size_t short_time_len(const char *line, size_t len)
  {
  	const char *time, *p;
  
  	if (len < strlen(" 07:01:32") || line[len-strlen(":32")] != ':')
  		return 0;
  	p = time = line + len - strlen(" 07:01:32");
  
  	/* Permit 1-digit hours? */
  	if (*p++ != ' ' ||
  	    !isdigit(*p++) || !isdigit(*p++) || *p++ != ':' ||
  	    !isdigit(*p++) || !isdigit(*p++) || *p++ != ':' ||
  	    !isdigit(*p++) || !isdigit(*p++))	/* Not a time. */
  		return 0;
  
  	return line + len - time;
  }
  
  static size_t fractional_time_len(const char *line, size_t len)
  {
  	const char *p;
  	size_t n;
  
  	/* Expected format: 19:41:17.620000023 */
  	if (!len || !isdigit(line[len - 1]))
  		return 0;
  	p = line + len - 1;
  
  	/* Fractional seconds. */
  	while (p > line && isdigit(*p))
  		p--;
  	if (*p != '.')
  		return 0;
  
  	/* Hours, minutes, and whole seconds. */
  	n = short_time_len(line, p - line);
  	if (!n)
  		return 0;
  
  	return line + len - p + n;
  }
  
  static size_t trailing_spaces_len(const char *line, size_t len)
  {
  	const char *p;
  
  	/* Expected format: ' ' x (1 or more)  */
  	if (!len || line[len - 1] != ' ')
  		return 0;
  
  	p = line + len;
  	while (p != line) {
  		p--;
  		if (*p != ' ')
  			return line + len - (p + 1);
  	}
  
  	/* All spaces! */
  	return len;
  }
  
  static size_t diff_timestamp_len(const char *line, size_t len)
  {
  	const char *end = line + len;
  	size_t n;
  
  	/*
  	 * Posix: 2010-07-05 19:41:17
  	 * GNU: 2010-07-05 19:41:17.620000023 -0500
  	 */
  
  	if (!isdigit(end[-1]))
  		return 0;
  
  	n = sane_tz_len(line, end - line);
  	if (!n)
  		n = tz_with_colon_len(line, end - line);
  	end -= n;
  
  	n = short_time_len(line, end - line);
  	if (!n)
  		n = fractional_time_len(line, end - line);
  	end -= n;
  
  	n = date_len(line, end - line);
  	if (!n)	/* No date.  Too bad. */
  		return 0;
  	end -= n;
  
  	if (end == line)	/* No space before date. */
  		return 0;
  	if (end[-1] == '\t') {	/* Success! */
  		end--;
  		return line + len - end;
  	}
  	if (end[-1] != ' ')	/* No space before date. */
  		return 0;
  
  	/* Whitespace damage. */
  	end -= trailing_spaces_len(line, end - line);
  	return line + len - end;
  }
  
  static char *find_name_common(struct strbuf *root,
  			      const char *line,
  			      const char *def,
  			      int p_value,
  			      const char *end,
  			      int terminate)
  {
  	int len;
  	const char *start = NULL;
  
  	if (p_value == 0)
  		start = line;
  	while (line != end) {
  		char c = *line;
  
  		if (!end && isspace(c)) {
  			if (c == '\n')
  				break;
  			if (name_terminate(c, terminate))
  				break;
  		}
  		line++;
  		if (c == '/' && !--p_value)
  			start = line;
  	}
  	if (!start)
  		return squash_slash(xstrdup_or_null(def));
  	len = line - start;
  	if (!len)
  		return squash_slash(xstrdup_or_null(def));
  
  	/*
  	 * Generally we prefer the shorter name, especially
  	 * if the other one is just a variation of that with
  	 * something else tacked on to the end (ie "file.orig"
  	 * or "file~").
  	 */
  	if (def) {
  		int deflen = strlen(def);
  		if (deflen < len && !strncmp(start, def, deflen))
  			return squash_slash(xstrdup(def));
  	}
  
  	if (root->len) {
  		char *ret = xstrfmt("%s%.*s", root->buf, len, start);
  		return squash_slash(ret);
  	}
  
  	return squash_slash(xmemdupz(start, len));
  }
  
  static char *find_name(struct strbuf *root,
  		       const char *line,
  		       char *def,
  		       int p_value,
  		       int terminate)
  {
  	if (*line == '"') {
  		char *name = find_name_gnu(root, line, p_value);
  		if (name)
  			return name;
  	}
  
  	return find_name_common(root, line, def, p_value, NULL, terminate);
  }
  
  static char *find_name_traditional(struct strbuf *root,
  				   const char *line,
  				   char *def,
  				   int p_value)
  {
  	size_t len;
  	size_t date_len;
  
  	if (*line == '"') {
  		char *name = find_name_gnu(root, line, p_value);
  		if (name)
  			return name;
  	}
  
  	len = strchrnul(line, '\n') - line;
  	date_len = diff_timestamp_len(line, len);
  	if (!date_len)
  		return find_name_common(root, line, def, p_value, NULL, TERM_TAB);
  	len -= date_len;
  
  	return find_name_common(root, line, def, p_value, line + len, 0);
  }
  
  /*
   * Given the string after "--- " or "+++ ", guess the appropriate
   * p_value for the given patch.
   */
  static int guess_p_value(struct apply_state *state, const char *nameline)
  {
  	char *name, *cp;
  	int val = -1;
  
  	if (is_dev_null(nameline))
  		return -1;
  	name = find_name_traditional(&state->root, nameline, NULL, 0);
  	if (!name)
  		return -1;
  	cp = strchr(name, '/');
  	if (!cp)
  		val = 0;
  	else if (state->prefix) {
  		/*
  		 * Does it begin with "a/$our-prefix" and such?  Then this is
  		 * very likely to apply to our directory.
  		 */
  		if (starts_with(name, state->prefix))
  			val = count_slashes(state->prefix);
  		else {
  			cp++;
  			if (starts_with(cp, state->prefix))
  				val = count_slashes(state->prefix) + 1;
  		}
  	}
  	free(name);
  	return val;
  }
  
  /*
   * Does the ---/+++ line have the POSIX timestamp after the last HT?
   * GNU diff puts epoch there to signal a creation/deletion event.  Is
   * this such a timestamp?
   */
  static int has_epoch_timestamp(const char *nameline)
  {
  	/*
  	 * We are only interested in epoch timestamp; any non-zero
  	 * fraction cannot be one, hence "(\.0+)?" in the regexp below.
  	 * For the same reason, the date must be either 1969-12-31 or
  	 * 1970-01-01, and the seconds part must be "00".
  	 */
  	const char stamp_regexp[] =
  		"^[0-2][0-9]:([0-5][0-9]):00(\\.0+)?"
  		" "
  		"([-+][0-2][0-9]:?[0-5][0-9])\n";
  	const char *timestamp = NULL, *cp, *colon;
  	static regex_t *stamp;
  	regmatch_t m[10];
  	int zoneoffset, epoch_hour, hour, minute;
  	int status;
  
  	for (cp = nameline; *cp != '\n'; cp++) {
  		if (*cp == '\t')
  			timestamp = cp + 1;
  	}
  	if (!timestamp)
  		return 0;
  
  	/*
  	 * YYYY-MM-DD hh:mm:ss must be from either 1969-12-31
  	 * (west of GMT) or 1970-01-01 (east of GMT)
  	 */
  	if (skip_prefix(timestamp, "1969-12-31 ", &timestamp))
  		epoch_hour = 24;
  	else if (skip_prefix(timestamp, "1970-01-01 ", &timestamp))
  		epoch_hour = 0;
  	else
  		return 0;
  
  	if (!stamp) {
  		stamp = xmalloc(sizeof(*stamp));
  		if (regcomp(stamp, stamp_regexp, REG_EXTENDED)) {
  			warning(_("Cannot prepare timestamp regexp %s"),
  				stamp_regexp);
  			return 0;
  		}
  	}
  
  	status = regexec(stamp, timestamp, ARRAY_SIZE(m), m, 0);
  	if (status) {
  		if (status != REG_NOMATCH)
  			warning(_("regexec returned %d for input: %s"),
  				status, timestamp);
  		return 0;
  	}
  
  	hour = strtol(timestamp, NULL, 10);
  	minute = strtol(timestamp + m[1].rm_so, NULL, 10);
  
  	zoneoffset = strtol(timestamp + m[3].rm_so + 1, (char **) &colon, 10);
  	if (*colon == ':')
  		zoneoffset = zoneoffset * 60 + strtol(colon + 1, NULL, 10);
  	else
  		zoneoffset = (zoneoffset / 100) * 60 + (zoneoffset % 100);
  	if (timestamp[m[3].rm_so] == '-')
  		zoneoffset = -zoneoffset;
  
  	return hour * 60 + minute - zoneoffset == epoch_hour * 60;
  }
  
  /*
   * Get the name etc info from the ---/+++ lines of a traditional patch header
   *
   * FIXME! The end-of-filename heuristics are kind of screwy. For existing
   * files, we can happily check the index for a match, but for creating a
   * new file we should try to match whatever "patch" does. I have no idea.
   */
  static int parse_traditional_patch(struct apply_state *state,
  				   const char *first,
  				   const char *second,
  				   struct patch *patch)
  {
  	char *name;
  
  	first += 4;	/* skip "--- " */
  	second += 4;	/* skip "+++ " */
  	if (!state->p_value_known) {
  		int p, q;
  		p = guess_p_value(state, first);
  		q = guess_p_value(state, second);
  		if (p < 0) p = q;
  		if (0 <= p && p == q) {
  			state->p_value = p;
  			state->p_value_known = 1;
  		}
  	}
  	if (is_dev_null(first)) {
  		patch->is_new = 1;
  		patch->is_delete = 0;
  		name = find_name_traditional(&state->root, second, NULL, state->p_value);
  		patch->new_name = name;
  	} else if (is_dev_null(second)) {
  		patch->is_new = 0;
  		patch->is_delete = 1;
  		name = find_name_traditional(&state->root, first, NULL, state->p_value);
  		patch->old_name = name;
  	} else {
  		char *first_name;
  		first_name = find_name_traditional(&state->root, first, NULL, state->p_value);
  		name = find_name_traditional(&state->root, second, first_name, state->p_value);
  		free(first_name);
  		if (has_epoch_timestamp(first)) {
  			patch->is_new = 1;
  			patch->is_delete = 0;
  			patch->new_name = name;
  		} else if (has_epoch_timestamp(second)) {
  			patch->is_new = 0;
  			patch->is_delete = 1;
  			patch->old_name = name;
  		} else {
  			patch->old_name = name;
  			patch->new_name = xstrdup_or_null(name);
  		}
  	}
  	if (!name)
  		return error(_("unable to find filename in patch at line %d"), state->linenr);
  
  	return 0;
  }
  
  static int gitdiff_hdrend(struct gitdiff_data *state,
  			  const char *line,
  			  struct patch *patch)
  {
  	return 1;
  }
  
  /*
   * We're anal about diff header consistency, to make
   * sure that we don't end up having strange ambiguous
   * patches floating around.
   *
   * As a result, gitdiff_{old|new}name() will check
   * their names against any previous information, just
   * to make sure..
   */
  #define DIFF_OLD_NAME 0
  #define DIFF_NEW_NAME 1
  
  static int gitdiff_verify_name(struct gitdiff_data *state,
  			       const char *line,
  			       int isnull,
  			       char **name,
  			       int side)
  {
  	if (!*name && !isnull) {
  		*name = find_name(state->root, line, NULL, state->p_value, TERM_TAB);
  		return 0;
  	}
  
  	if (*name) {
  		char *another;
  		if (isnull)
  			return error(_("git apply: bad git-diff - expected /dev/null, got %s on line %d"),
  				     *name, state->linenr);
  		another = find_name(state->root, line, NULL, state->p_value, TERM_TAB);
  		if (!another || strcmp(another, *name)) {
  			free(another);
  			return error((side == DIFF_NEW_NAME) ?
  			    _("git apply: bad git-diff - inconsistent new filename on line %d") :
  			    _("git apply: bad git-diff - inconsistent old filename on line %d"), state->linenr);
  		}
  		free(another);
  	} else {
  		if (!is_dev_null(line))
  			return error(_("git apply: bad git-diff - expected /dev/null on line %d"), state->linenr);
  	}
  
  	return 0;
  }
  
  static int gitdiff_oldname(struct gitdiff_data *state,
  			   const char *line,
  			   struct patch *patch)
  {
  	return gitdiff_verify_name(state, line,
  				   patch->is_new, &patch->old_name,
  				   DIFF_OLD_NAME);
  }
  
  static int gitdiff_newname(struct gitdiff_data *state,
  			   const char *line,
  			   struct patch *patch)
  {
  	return gitdiff_verify_name(state, line,
  				   patch->is_delete, &patch->new_name,
  				   DIFF_NEW_NAME);
  }
  
  static int parse_mode_line(const char *line, int linenr, unsigned int *mode)
  {
  	char *end;
  	*mode = strtoul(line, &end, 8);
  	if (end == line || !isspace(*end))
  		return error(_("invalid mode on line %d: %s"), linenr, line);
  	return 0;
  }
  
  static int gitdiff_oldmode(struct gitdiff_data *state,
  			   const char *line,
  			   struct patch *patch)
  {
  	return parse_mode_line(line, state->linenr, &patch->old_mode);
  }
  
  static int gitdiff_newmode(struct gitdiff_data *state,
  			   const char *line,
  			   struct patch *patch)
  {
  	return parse_mode_line(line, state->linenr, &patch->new_mode);
  }
  
  static int gitdiff_delete(struct gitdiff_data *state,
  			  const char *line,
  			  struct patch *patch)
  {
  	patch->is_delete = 1;
  	free(patch->old_name);
  	patch->old_name = xstrdup_or_null(patch->def_name);
  	return gitdiff_oldmode(state, line, patch);
  }
  
  static int gitdiff_newfile(struct gitdiff_data *state,
  			   const char *line,
  			   struct patch *patch)
  {
  	patch->is_new = 1;
  	free(patch->new_name);
  	patch->new_name = xstrdup_or_null(patch->def_name);
  	return gitdiff_newmode(state, line, patch);
  }
  
  static int gitdiff_copysrc(struct gitdiff_data *state,
  			   const char *line,
  			   struct patch *patch)
  {
  	patch->is_copy = 1;
  	free(patch->old_name);
  	patch->old_name = find_name(state->root, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
  	return 0;
  }
  
  static int gitdiff_copydst(struct gitdiff_data *state,
  			   const char *line,
  			   struct patch *patch)
  {
  	patch->is_copy = 1;
  	free(patch->new_name);
  	patch->new_name = find_name(state->root, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
  	return 0;
  }
  
  static int gitdiff_renamesrc(struct gitdiff_data *state,
  			     const char *line,
  			     struct patch *patch)
  {
  	patch->is_rename = 1;
  	free(patch->old_name);
  	patch->old_name = find_name(state->root, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
  	return 0;
  }
  
  static int gitdiff_renamedst(struct gitdiff_data *state,
  			     const char *line,
  			     struct patch *patch)
  {
  	patch->is_rename = 1;
  	free(patch->new_name);
  	patch->new_name = find_name(state->root, line, NULL, state->p_value ? state->p_value - 1 : 0, 0);
  	return 0;
  }
  
  static int gitdiff_similarity(struct gitdiff_data *state,
  			      const char *line,
  			      struct patch *patch)
  {
  	unsigned long val = strtoul(line, NULL, 10);
  	if (val <= 100)
  		patch->score = val;
  	return 0;
  }
  
  static int gitdiff_dissimilarity(struct gitdiff_data *state,
  				 const char *line,
  				 struct patch *patch)
  {
  	unsigned long val = strtoul(line, NULL, 10);
  	if (val <= 100)
  		patch->score = val;
  	return 0;
  }
  
  static int gitdiff_index(struct gitdiff_data *state,
  			 const char *line,
  			 struct patch *patch)
  {
  	/*
  	 * index line is N hexadecimal, "..", N hexadecimal,
  	 * and optional space with octal mode.
  	 */
  	const char *ptr, *eol;
  	int len;
  	const unsigned hexsz = the_hash_algo->hexsz;
  
  	ptr = strchr(line, '.');
  	if (!ptr || ptr[1] != '.' || hexsz < ptr - line)
  		return 0;
  	len = ptr - line;
  	memcpy(patch->old_oid_prefix, line, len);
  	patch->old_oid_prefix[len] = 0;
  
  	line = ptr + 2;
  	ptr = strchr(line, ' ');
  	eol = strchrnul(line, '\n');
  
  	if (!ptr || eol < ptr)
  		ptr = eol;
  	len = ptr - line;
  
  	if (hexsz < len)
  		return 0;
  	memcpy(patch->new_oid_prefix, line, len);
  	patch->new_oid_prefix[len] = 0;
  	if (*ptr == ' ')
  		return gitdiff_oldmode(state, ptr + 1, patch);
  	return 0;
  }
  
  /*
   * This is normal for a diff that doesn't change anything: we'll fall through
   * into the next diff. Tell the parser to break out.
   */
  static int gitdiff_unrecognized(struct gitdiff_data *state,
  				const char *line,
  				struct patch *patch)
  {
  	return 1;
  }
  
  /*
   * Skip p_value leading components from "line"; as we do not accept
   * absolute paths, return NULL in that case.
   */
  static const char *skip_tree_prefix(int p_value,
  				    const char *line,
  				    int llen)
  {
  	int nslash;
  	int i;
  
  	if (!p_value)
  		return (llen && line[0] == '/') ? NULL : line;
  
  	nslash = p_value;
  	for (i = 0; i < llen; i++) {
  		int ch = line[i];
  		if (ch == '/' && --nslash <= 0)
  			return (i == 0) ? NULL : &line[i + 1];
  	}
  	return NULL;
  }
  
  /*
   * This is to extract the same name that appears on "diff --git"
   * line.  We do not find and return anything if it is a rename
   * patch, and it is OK because we will find the name elsewhere.
   * We need to reliably find name only when it is mode-change only,
   * creation or deletion of an empty file.  In any of these cases,
   * both sides are the same name under a/ and b/ respectively.
   */
  static char *git_header_name(int p_value,
  			     const char *line,
  			     int llen)
  {
  	const char *name;
  	const char *second = NULL;
  	size_t len, line_len;
  
  	line += strlen("diff --git ");
  	llen -= strlen("diff --git ");
  
  	if (*line == '"') {
  		const char *cp;
  		struct strbuf first = STRBUF_INIT;
  		struct strbuf sp = STRBUF_INIT;
  
  		if (unquote_c_style(&first, line, &second))
  			goto free_and_fail1;
  
  		/* strip the a/b prefix including trailing slash */
  		cp = skip_tree_prefix(p_value, first.buf, first.len);
  		if (!cp)
  			goto free_and_fail1;
  		strbuf_remove(&first, 0, cp - first.buf);
  
  		/*
  		 * second points at one past closing dq of name.
  		 * find the second name.
  		 */
  		while ((second < line + llen) && isspace(*second))
  			second++;
  
  		if (line + llen <= second)
  			goto free_and_fail1;
  		if (*second == '"') {
  			if (unquote_c_style(&sp, second, NULL))
  				goto free_and_fail1;
  			cp = skip_tree_prefix(p_value, sp.buf, sp.len);
  			if (!cp)
  				goto free_and_fail1;
  			/* They must match, otherwise ignore */
  			if (strcmp(cp, first.buf))
  				goto free_and_fail1;
  			strbuf_release(&sp);
  			return strbuf_detach(&first, NULL);
  		}
  
  		/* unquoted second */
  		cp = skip_tree_prefix(p_value, second, line + llen - second);
  		if (!cp)
  			goto free_and_fail1;
  		if (line + llen - cp != first.len ||
  		    memcmp(first.buf, cp, first.len))
  			goto free_and_fail1;
  		return strbuf_detach(&first, NULL);
  
  	free_and_fail1:
  		strbuf_release(&first);
  		strbuf_release(&sp);
  		return NULL;
  	}
  
  	/* unquoted first name */
  	name = skip_tree_prefix(p_value, line, llen);
  	if (!name)
  		return NULL;
  
  	/*
  	 * since the first name is unquoted, a dq if exists must be
  	 * the beginning of the second name.
  	 */
  	for (second = name; second < line + llen; second++) {
  		if (*second == '"') {
  			struct strbuf sp = STRBUF_INIT;
  			const char *np;
  
  			if (unquote_c_style(&sp, second, NULL))
  				goto free_and_fail2;
  
  			np = skip_tree_prefix(p_value, sp.buf, sp.len);
  			if (!np)
  				goto free_and_fail2;
  
  			len = sp.buf + sp.len - np;
  			if (len < second - name &&
  			    !strncmp(np, name, len) &&
  			    isspace(name[len])) {
  				/* Good */
  				strbuf_remove(&sp, 0, np - sp.buf);
  				return strbuf_detach(&sp, NULL);
  			}
  
  		free_and_fail2:
  			strbuf_release(&sp);
  			return NULL;
  		}
  	}
  
  	/*
  	 * Accept a name only if it shows up twice, exactly the same
  	 * form.
  	 */
  	second = strchr(name, '\n');
  	if (!second)
  		return NULL;
  	line_len = second - name;
  	for (len = 0 ; ; len++) {
  		switch (name[len]) {
  		default:
  			continue;
  		case '\n':
  			return NULL;
  		case '\t': case ' ':
  			/*
  			 * Is this the separator between the preimage
  			 * and the postimage pathname?  Again, we are
  			 * only interested in the case where there is
  			 * no rename, as this is only to set def_name
  			 * and a rename patch has the names elsewhere
  			 * in an unambiguous form.
  			 */
  			if (!name[len + 1])
  				return NULL; /* no postimage name */
  			second = skip_tree_prefix(p_value, name + len + 1,
  						  line_len - (len + 1));
  			if (!second)
  				return NULL;
  			/*
  			 * Does len bytes starting at "name" and "second"
  			 * (that are separated by one HT or SP we just
  			 * found) exactly match?
  			 */
  			if (second[len] == '\n' && !strncmp(name, second, len))
  				return xmemdupz(name, len);
  		}
  	}
  }
  
  static int check_header_line(int linenr, struct patch *patch)
  {
  	int extensions = (patch->is_delete == 1) + (patch->is_new == 1) +
  			 (patch->is_rename == 1) + (patch->is_copy == 1);
  	if (extensions > 1)
  		return error(_("inconsistent header lines %d and %d"),
  			     patch->extension_linenr, linenr);
  	if (extensions && !patch->extension_linenr)
  		patch->extension_linenr = linenr;
  	return 0;
  }
  
  int parse_git_diff_header(struct strbuf *root,
  			  int *linenr,
  			  int p_value,
  			  const char *line,
  			  int len,
  			  unsigned int size,
  			  struct patch *patch)
  {
  	unsigned long offset;
  	struct gitdiff_data parse_hdr_state;
  
  	/* A git diff has explicit new/delete information, so we don't guess */
  	patch->is_new = 0;
  	patch->is_delete = 0;
  
  	/*
  	 * Some things may not have the old name in the
  	 * rest of the headers anywhere (pure mode changes,
  	 * or removing or adding empty files), so we get
  	 * the default name from the header.
  	 */
  	patch->def_name = git_header_name(p_value, line, len);
  	if (patch->def_name && root->len) {
  		char *s = xstrfmt("%s%s", root->buf, patch->def_name);
  		free(patch->def_name);
  		patch->def_name = s;
  	}
  
  	line += len;
  	size -= len;
  	(*linenr)++;
  	parse_hdr_state.root = root;
  	parse_hdr_state.linenr = *linenr;
  	parse_hdr_state.p_value = p_value;
  
  	for (offset = len ; size > 0 ; offset += len, size -= len, line += len, (*linenr)++) {
  		static const struct opentry {
  			const char *str;
  			int (*fn)(struct gitdiff_data *, const char *, struct patch *);
  		} optable[] = {
  			{ "@@ -", gitdiff_hdrend },
  			{ "--- ", gitdiff_oldname },
  			{ "+++ ", gitdiff_newname },
  			{ "old mode ", gitdiff_oldmode },
  			{ "new mode ", gitdiff_newmode },
  			{ "deleted file mode ", gitdiff_delete },
  			{ "new file mode ", gitdiff_newfile },
  			{ "copy from ", gitdiff_copysrc },
  			{ "copy to ", gitdiff_copydst },
  			{ "rename old ", gitdiff_renamesrc },
  			{ "rename new ", gitdiff_renamedst },
  			{ "rename from ", gitdiff_renamesrc },
  			{ "rename to ", gitdiff_renamedst },
  			{ "similarity index ", gitdiff_similarity },
  			{ "dissimilarity index ", gitdiff_dissimilarity },
  			{ "index ", gitdiff_index },
  			{ "", gitdiff_unrecognized },
  		};
  		int i;
  
  		len = linelen(line, size);
  		if (!len || line[len-1] != '\n')
  			break;
  		for (i = 0; i < ARRAY_SIZE(optable); i++) {
  			const struct opentry *p = optable + i;
  			int oplen = strlen(p->str);
  			int res;
  			if (len < oplen || memcmp(p->str, line, oplen))
  				continue;
  			res = p->fn(&parse_hdr_state, line + oplen, patch);
  			if (res < 0)
  				return -1;
  			if (check_header_line(*linenr, patch))
  				return -1;
  			if (res > 0)
  				return offset;
  			break;
  		}
  	}
  
  	return offset;
  }
  
  static int parse_num(const char *line, unsigned long *p)
  {
  	char *ptr;
  
  	if (!isdigit(*line))
  		return 0;
  	*p = strtoul(line, &ptr, 10);
  	return ptr - line;
  }
  
  static int parse_range(const char *line, int len, int offset, const char *expect,
  		       unsigned long *p1, unsigned long *p2)
  {
  	int digits, ex;
  
  	if (offset < 0 || offset >= len)
  		return -1;
  	line += offset;
  	len -= offset;
  
  	digits = parse_num(line, p1);
  	if (!digits)
  		return -1;
  
  	offset += digits;
  	line += digits;
  	len -= digits;
  
  	*p2 = 1;
  	if (*line == ',') {
  		digits = parse_num(line+1, p2);
  		if (!digits)
  			return -1;
  
  		offset += digits+1;
  		line += digits+1;
  		len -= digits+1;
  	}
  
  	ex = strlen(expect);
  	if (ex > len)
  		return -1;
  	if (memcmp(line, expect, ex))
  		return -1;
  
  	return offset + ex;
  }
  
  static void recount_diff(const char *line, int size, struct fragment *fragment)
  {
  	int oldlines = 0, newlines = 0, ret = 0;
  
  	if (size < 1) {
  		warning("recount: ignore empty hunk");
  		return;
  	}
  
  	for (;;) {
  		int len = linelen(line, size);
  		size -= len;
  		line += len;
  
  		if (size < 1)
  			break;
  
  		switch (*line) {
  		case ' ': case '\n':
  			newlines++;
  			/* fall through */
  		case '-':
  			oldlines++;
  			continue;
  		case '+':
  			newlines++;
  			continue;
  		case '\\':
  			continue;
  		case '@':
  			ret = size < 3 || !starts_with(line, "@@ ");
  			break;
  		case 'd':
  			ret = size < 5 || !starts_with(line, "diff ");
  			break;
  		default:
  			ret = -1;
  			break;
  		}
  		if (ret) {
  			warning(_("recount: unexpected line: %.*s"),
  				(int)linelen(line, size), line);
  			return;
  		}
  		break;
  	}
  	fragment->oldlines = oldlines;
  	fragment->newlines = newlines;
  }
  
  /*
   * Parse a unified diff fragment header of the
   * form "@@ -a,b +c,d @@"
   */
  static int parse_fragment_header(const char *line, int len, struct fragment *fragment)
  {
  	int offset;
  
  	if (!len || line[len-1] != '\n')
  		return -1;
  
  	/* Figure out the number of lines in a fragment */
  	offset = parse_range(line, len, 4, " +", &fragment->oldpos, &fragment->oldlines);
  	offset = parse_range(line, len, offset, " @@", &fragment->newpos, &fragment->newlines);
  
  	return offset;
  }
  
  /*
   * Find file diff header
   *
   * Returns:
   *  -1 if no header was found
   *  -128 in case of error
   *   the size of the header in bytes (called "offset") otherwise
   */
  static int find_header(struct apply_state *state,
  		       const char *line,
  		       unsigned long size,
  		       int *hdrsize,
  		       struct patch *patch)
  {
  	unsigned long offset, len;
  
  	patch->is_toplevel_relative = 0;
  	patch->is_rename = patch->is_copy = 0;
  	patch->is_new = patch->is_delete = -1;
  	patch->old_mode = patch->new_mode = 0;
  	patch->old_name = patch->new_name = NULL;
  	for (offset = 0; size > 0; offset += len, size -= len, line += len, state->linenr++) {
  		unsigned long nextlen;
  
  		len = linelen(line, size);
  		if (!len)
  			break;
  
  		/* Testing this early allows us to take a few shortcuts.. */
  		if (len < 6)
  			continue;
  
  		/*
  		 * Make sure we don't find any unconnected patch fragments.
  		 * That's a sign that we didn't find a header, and that a
  		 * patch has become corrupted/broken up.
  		 */
  		if (!memcmp("@@ -", line, 4)) {
  			struct fragment dummy;
  			if (parse_fragment_header(line, len, &dummy) < 0)
  				continue;
  			error(_("patch fragment without header at line %d: %.*s"),
  				     state->linenr, (int)len-1, line);
  			return -128;
  		}
  
  		if (size < len + 6)
  			break;
  
  		/*
  		 * Git patch? It might not have a real patch, just a rename
  		 * or mode change, so we handle that specially
  		 */
  		if (!memcmp("diff --git ", line, 11)) {
  			int git_hdr_len = parse_git_diff_header(&state->root, &state->linenr,
  								state->p_value, line, len,
  								size, patch);
  			if (git_hdr_len < 0)
  				return -128;
  			if (git_hdr_len <= len)
  				continue;
  			if (!patch->old_name && !patch->new_name) {
  				if (!patch->def_name) {
  					error(Q_("git diff header lacks filename information when removing "
  							"%d leading pathname component (line %d)",
  							"git diff header lacks filename information when removing "
  							"%d leading pathname components (line %d)",
  							state->p_value),
  						     state->p_value, state->linenr);
  					return -128;
  				}
  				patch->old_name = xstrdup(patch->def_name);
  				patch->new_name = xstrdup(patch->def_name);
  			}
  			if ((!patch->new_name && !patch->is_delete) ||
  			    (!patch->old_name && !patch->is_new)) {
  				error(_("git diff header lacks filename information "
  					     "(line %d)"), state->linenr);
  				return -128;
  			}
  			patch->is_toplevel_relative = 1;
  			*hdrsize = git_hdr_len;
  			return offset;
  		}
  
  		/* --- followed by +++ ? */
  		if (memcmp("--- ", line,  4) || memcmp("+++ ", line + len, 4))
  			continue;
  
  		/*
  		 * We only accept unified patches, so we want it to
  		 * at least have "@@ -a,b +c,d @@\n", which is 14 chars
  		 * minimum ("@@ -0,0 +1 @@\n" is the shortest).
  		 */
  		nextlen = linelen(line + len, size - len);
  		if (size < nextlen + 14 || memcmp("@@ -", line + len + nextlen, 4))
  			continue;
  
  		/* Ok, we'll consider it a patch */
  		if (parse_traditional_patch(state, line, line+len, patch))
  			return -128;
  		*hdrsize = len + nextlen;
  		state->linenr += 2;
  		return offset;
  	}
  	return -1;
  }
  
  static void record_ws_error(struct apply_state *state,
  			    unsigned result,
  			    const char *line,
  			    int len,
  			    int linenr)
  {
  	char *err;
  
  	if (!result)
  		return;
  
  	state->whitespace_error++;
  	if (state->squelch_whitespace_errors &&
  	    state->squelch_whitespace_errors < state->whitespace_error)
  		return;
  
  	err = whitespace_error_string(result);
  	if (state->apply_verbosity > verbosity_silent)
  		fprintf(stderr, "%s:%d: %s.\n%.*s\n",
  			state->patch_input_file, linenr, err, len, line);
  	free(err);
  }
  
  static void check_whitespace(struct apply_state *state,
  			     const char *line,
  			     int len,
  			     unsigned ws_rule)
  {
  	unsigned result = ws_check(line + 1, len - 1, ws_rule);
  
  	record_ws_error(state, result, line + 1, len - 2, state->linenr);
  }
  
  /*
   * Check if the patch has context lines with CRLF or
   * the patch wants to remove lines with CRLF.
   */
  static void check_old_for_crlf(struct patch *patch, const char *line, int len)
  {
  	if (len >= 2 && line[len-1] == '\n' && line[len-2] == '\r') {
  		patch->ws_rule |= WS_CR_AT_EOL;
  		patch->crlf_in_old = 1;
  	}
  }
  
  
  /*
   * Parse a unified diff. Note that this really needs to parse each
   * fragment separately, since the only way to know the difference
   * between a "---" that is part of a patch, and a "---" that starts
   * the next patch is to look at the line counts..
   */
  static int parse_fragment(struct apply_state *state,
  			  const char *line,
  			  unsigned long size,
  			  struct patch *patch,
  			  struct fragment *fragment)
  {
  	int added, deleted;
  	int len = linelen(line, size), offset;
  	unsigned long oldlines, newlines;
  	unsigned long leading, trailing;
  
  	offset = parse_fragment_header(line, len, fragment);
  	if (offset < 0)
  		return -1;
  	if (offset > 0 && patch->recount)
  		recount_diff(line + offset, size - offset, fragment);
  	oldlines = fragment->oldlines;
  	newlines = fragment->newlines;
  	leading = 0;
  	trailing = 0;
  
  	/* Parse the thing.. */
  	line += len;
  	size -= len;
  	state->linenr++;
  	added = deleted = 0;
  	for (offset = len;
  	     0 < size;
  	     offset += len, size -= len, line += len, state->linenr++) {
  		if (!oldlines && !newlines)
  			break;
  		len = linelen(line, size);
  		if (!len || line[len-1] != '\n')
  			return -1;
  		switch (*line) {
  		default:
  			return -1;
  		case '\n': /* newer GNU diff, an empty context line */
  		case ' ':
  			oldlines--;
  			newlines--;
  			if (!deleted && !added)
  				leading++;
  			trailing++;
  			check_old_for_crlf(patch, line, len);
  			if (!state->apply_in_reverse &&
  			    state->ws_error_action == correct_ws_error)
  				check_whitespace(state, line, len, patch->ws_rule);
  			break;
  		case '-':
  			if (!state->apply_in_reverse)
  				check_old_for_crlf(patch, line, len);
  			if (state->apply_in_reverse &&
  			    state->ws_error_action != nowarn_ws_error)
  				check_whitespace(state, line, len, patch->ws_rule);
  			deleted++;
  			oldlines--;
  			trailing = 0;
  			break;
  		case '+':
  			if (state->apply_in_reverse)
  				check_old_for_crlf(patch, line, len);
  			if (!state->apply_in_reverse &&
  			    state->ws_error_action != nowarn_ws_error)
  				check_whitespace(state, line, len, patch->ws_rule);
  			added++;
  			newlines--;
  			trailing = 0;
  			break;
  
  		/*
  		 * We allow "\ No newline at end of file". Depending
  		 * on locale settings when the patch was produced we
  		 * don't know what this line looks like. The only
  		 * thing we do know is that it begins with "\ ".
  		 * Checking for 12 is just for sanity check -- any
  		 * l10n of "\ No newline..." is at least that long.
  		 */
  		case '\\':
  			if (len < 12 || memcmp(line, "\\ ", 2))
  				return -1;
  			break;
  		}
  	}
  	if (oldlines || newlines)
  		return -1;
  	if (!patch->recount && !deleted && !added)
  		return -1;
  
  	fragment->leading = leading;
  	fragment->trailing = trailing;
  
  	/*
  	 * If a fragment ends with an incomplete line, we failed to include
  	 * it in the above loop because we hit oldlines == newlines == 0
  	 * before seeing it.
  	 */
  	if (12 < size && !memcmp(line, "\\ ", 2))
  		offset += linelen(line, size);
  
  	patch->lines_added += added;
  	patch->lines_deleted += deleted;
  
  	if (0 < patch->is_new && oldlines)
  		return error(_("new file depends on old contents"));
  	if (0 < patch->is_delete && newlines)
  		return error(_("deleted file still has contents"));
  	return offset;
  }
  
  /*
   * We have seen "diff --git a/... b/..." header (or a traditional patch
   * header).  Read hunks that belong to this patch into fragments and hang
   * them to the given patch structure.
   *
   * The (fragment->patch, fragment->size) pair points into the memory given
   * by the caller, not a copy, when we return.
   *
   * Returns:
   *   -1 in case of error,
   *   the number of bytes in the patch otherwise.
   */
  static int parse_single_patch(struct apply_state *state,
  			      const char *line,
  			      unsigned long size,
  			      struct patch *patch)
  {
  	unsigned long offset = 0;
  	unsigned long oldlines = 0, newlines = 0, context = 0;
  	struct fragment **fragp = &patch->fragments;
  
  	while (size > 4 && !memcmp(line, "@@ -", 4)) {
  		struct fragment *fragment;
  		int len;
  
  		fragment = xcalloc(1, sizeof(*fragment));
  		fragment->linenr = state->linenr;
  		len = parse_fragment(state, line, size, patch, fragment);
  		if (len <= 0) {
  			free(fragment);
  			return error(_("corrupt patch at line %d"), state->linenr);
  		}
  		fragment->patch = line;
  		fragment->size = len;
  		oldlines += fragment->oldlines;
  		newlines += fragment->newlines;
  		context += fragment->leading + fragment->trailing;
  
  		*fragp = fragment;
  		fragp = &fragment->next;
  
  		offset += len;
  		line += len;
  		size -= len;
  	}
  
  	/*
  	 * If something was removed (i.e. we have old-lines) it cannot
  	 * be creation, and if something was added it cannot be
  	 * deletion.  However, the reverse is not true; --unified=0
  	 * patches that only add are not necessarily creation even
  	 * though they do not have any old lines, and ones that only
  	 * delete are not necessarily deletion.
  	 *
  	 * Unfortunately, a real creation/deletion patch do _not_ have
  	 * any context line by definition, so we cannot safely tell it
  	 * apart with --unified=0 insanity.  At least if the patch has
  	 * more than one hunk it is not creation or deletion.
  	 */
  	if (patch->is_new < 0 &&
  	    (oldlines || (patch->fragments && patch->fragments->next)))
  		patch->is_new = 0;
  	if (patch->is_delete < 0 &&
  	    (newlines || (patch->fragments && patch->fragments->next)))
  		patch->is_delete = 0;
  
  	if (0 < patch->is_new && oldlines)
  		return error(_("new file %s depends on old contents"), patch->new_name);
  	if (0 < patch->is_delete && newlines)
  		return error(_("deleted file %s still has contents"), patch->old_name);
  	if (!patch->is_delete && !newlines && context && state->apply_verbosity > verbosity_silent)
  		fprintf_ln(stderr,
  			   _("** warning: "
  			     "file %s becomes empty but is not deleted"),
  			   patch->new_name);
  
  	return offset;
  }
  
  static inline int metadata_changes(struct patch *patch)
  {
  	return	patch->is_rename > 0 ||
  		patch->is_copy > 0 ||
  		patch->is_new > 0 ||
  		patch->is_delete ||
  		(patch->old_mode && patch->new_mode &&
  		 patch->old_mode != patch->new_mode);
  }
  
  static char *inflate_it(const void *data, unsigned long size,
  			unsigned long inflated_size)
  {
  	git_zstream stream;
  	void *out;
  	int st;
  
  	memset(&stream, 0, sizeof(stream));
  
  	stream.next_in = (unsigned char *)data;
  	stream.avail_in = size;
  	stream.next_out = out = xmalloc(inflated_size);
  	stream.avail_out = inflated_size;
  	git_inflate_init(&stream);
  	st = git_inflate(&stream, Z_FINISH);
  	git_inflate_end(&stream);
  	if ((st != Z_STREAM_END) || stream.total_out != inflated_size) {
  		free(out);
  		return NULL;
  	}
  	return out;
  }
  
  /*
   * Read a binary hunk and return a new fragment; fragment->patch
   * points at an allocated memory that the caller must free, so
   * it is marked as "->free_patch = 1".
   */
  static struct fragment *parse_binary_hunk(struct apply_state *state,
  					  char **buf_p,
  					  unsigned long *sz_p,
  					  int *status_p,
  					  int *used_p)
  {
  	/*
  	 * Expect a line that begins with binary patch method ("literal"
  	 * or "delta"), followed by the length of data before deflating.
  	 * a sequence of 'length-byte' followed by base-85 encoded data
  	 * should follow, terminated by a newline.
  	 *
  	 * Each 5-byte sequence of base-85 encodes up to 4 bytes,
  	 * and we would limit the patch line to 66 characters,
  	 * so one line can fit up to 13 groups that would decode
  	 * to 52 bytes max.  The length byte 'A'-'Z' corresponds
  	 * to 1-26 bytes, and 'a'-'z' corresponds to 27-52 bytes.
  	 */
  	int llen, used;
  	unsigned long size = *sz_p;
  	char *buffer = *buf_p;
  	int patch_method;
  	unsigned long origlen;
  	char *data = NULL;
  	int hunk_size = 0;
  	struct fragment *frag;
  
  	llen = linelen(buffer, size);
  	used = llen;
  
  	*status_p = 0;
  
  	if (starts_with(buffer, "delta ")) {
  		patch_method = BINARY_DELTA_DEFLATED;
  		origlen = strtoul(buffer + 6, NULL, 10);
  	}
  	else if (starts_with(buffer, "literal ")) {
  		patch_method = BINARY_LITERAL_DEFLATED;
  		origlen = strtoul(buffer + 8, NULL, 10);
  	}
  	else
  		return NULL;
  
  	state->linenr++;
  	buffer += llen;
  	while (1) {
  		int byte_length, max_byte_length, newsize;
  		llen = linelen(buffer, size);
  		used += llen;
  		state->linenr++;
  		if (llen == 1) {
  			/* consume the blank line */
  			buffer++;
  			size--;
  			break;
  		}
  		/*
  		 * Minimum line is "A00000\n" which is 7-byte long,
  		 * and the line length must be multiple of 5 plus 2.
  		 */
  		if ((llen < 7) || (llen-2) % 5)
  			goto corrupt;
  		max_byte_length = (llen - 2) / 5 * 4;
  		byte_length = *buffer;
  		if ('A' <= byte_length && byte_length <= 'Z')
  			byte_length = byte_length - 'A' + 1;
  		else if ('a' <= byte_length && byte_length <= 'z')
  			byte_length = byte_length - 'a' + 27;
  		else
  			goto corrupt;
  		/* if the input length was not multiple of 4, we would
  		 * have filler at the end but the filler should never
  		 * exceed 3 bytes
  		 */
  		if (max_byte_length < byte_length ||
  		    byte_length <= max_byte_length - 4)
  			goto corrupt;
  		newsize = hunk_size + byte_length;
  		data = xrealloc(data, newsize);
  		if (decode_85(data + hunk_size, buffer + 1, byte_length))
  			goto corrupt;
  		hunk_size = newsize;
  		buffer += llen;
  		size -= llen;
  	}
  
  	frag = xcalloc(1, sizeof(*frag));
  	frag->patch = inflate_it(data, hunk_size, origlen);
  	frag->free_patch = 1;
  	if (!frag->patch)
  		goto corrupt;
  	free(data);
  	frag->size = origlen;
  	*buf_p = buffer;
  	*sz_p = size;
  	*used_p = used;
  	frag->binary_patch_method = patch_method;
  	return frag;
  
   corrupt:
  	free(data);
  	*status_p = -1;
  	error(_("corrupt binary patch at line %d: %.*s"),
  	      state->linenr-1, llen-1, buffer);
  	return NULL;
  }
  
  /*
   * Returns:
   *   -1 in case of error,
   *   the length of the parsed binary patch otherwise
   */
  static int parse_binary(struct apply_state *state,
  			char *buffer,
  			unsigned long size,
  			struct patch *patch)
  {
  	/*
  	 * We have read "GIT binary patch\n"; what follows is a line
  	 * that says the patch method (currently, either "literal" or
  	 * "delta") and the length of data before deflating; a
  	 * sequence of 'length-byte' followed by base-85 encoded data
  	 * follows.
  	 *
  	 * When a binary patch is reversible, there is another binary
  	 * hunk in the same format, starting with patch method (either
  	 * "literal" or "delta") with the length of data, and a sequence
  	 * of length-byte + base-85 encoded data, terminated with another
  	 * empty line.  This data, when applied to the postimage, produces
  	 * the preimage.
  	 */
  	struct fragment *forward;
  	struct fragment *reverse;
  	int status;
  	int used, used_1;
  
  	forward = parse_binary_hunk(state, &buffer, &size, &status, &used);
  	if (!forward && !status)
  		/* there has to be one hunk (forward hunk) */
  		return error(_("unrecognized binary patch at line %d"), state->linenr-1);
  	if (status)
  		/* otherwise we already gave an error message */
  		return status;
  
  	reverse = parse_binary_hunk(state, &buffer, &size, &status, &used_1);
  	if (reverse)
  		used += used_1;
  	else if (status) {
  		/*
  		 * Not having reverse hunk is not an error, but having
  		 * a corrupt reverse hunk is.
  		 */
  		free((void*) forward->patch);
  		free(forward);
  		return status;
  	}
  	forward->next = reverse;
  	patch->fragments = forward;
  	patch->is_binary = 1;
  	return used;
  }
  
  static void prefix_one(struct apply_state *state, char **name)
  {
  	char *old_name = *name;
  	if (!old_name)
  		return;
  	*name = prefix_filename(state->prefix, *name);
  	free(old_name);
  }
  
  static void prefix_patch(struct apply_state *state, struct patch *p)
  {
  	if (!state->prefix || p->is_toplevel_relative)
  		return;
  	prefix_one(state, &p->new_name);
  	prefix_one(state, &p->old_name);
  }
  
  /*
   * include/exclude
   */
  
  static void add_name_limit(struct apply_state *state,
  			   const char *name,
  			   int exclude)
  {
  	struct string_list_item *it;
  
  	it = string_list_append(&state->limit_by_name, name);
  	it->util = exclude ? NULL : (void *) 1;
  }
  
  static int use_patch(struct apply_state *state, struct patch *p)
  {
  	const char *pathname = p->new_name ? p->new_name : p->old_name;
  	int i;
  
  	/* Paths outside are not touched regardless of "--include" */
  	if (state->prefix && *state->prefix) {
  		const char *rest;
  		if (!skip_prefix(pathname, state->prefix, &rest) || !*rest)
  			return 0;
  	}
  
  	/* See if it matches any of exclude/include rule */
  	for (i = 0; i < state->limit_by_name.nr; i++) {
  		struct string_list_item *it = &state->limit_by_name.items[i];
  		if (!wildmatch(it->string, pathname, 0))
  			return (it->util != NULL);
  	}
  
  	/*
  	 * If we had any include, a path that does not match any rule is
  	 * not used.  Otherwise, we saw bunch of exclude rules (or none)
  	 * and such a path is used.
  	 */
  	return !state->has_include;
  }
  
  /*
   * Read the patch text in "buffer" that extends for "size" bytes; stop
   * reading after seeing a single patch (i.e. changes to a single file).
   * Create fragments (i.e. patch hunks) and hang them to the given patch.
   *
   * Returns:
   *   -1 if no header was found or parse_binary() failed,
   *   -128 on another error,
   *   the number of bytes consumed otherwise,
   *     so that the caller can call us again for the next patch.
   */
  static int parse_chunk(struct apply_state *state, char *buffer, unsigned long size, struct patch *patch)
  {
  	int hdrsize, patchsize;
  	int offset = find_header(state, buffer, size, &hdrsize, patch);
  
  	if (offset < 0)
  		return offset;
  
  	prefix_patch(state, patch);
  
  	if (!use_patch(state, patch))
  		patch->ws_rule = 0;
  	else if (patch->new_name)
  		patch->ws_rule = whitespace_rule(state->repo->index,
  						 patch->new_name);
  	else
  		patch->ws_rule = whitespace_rule(state->repo->index,
  						 patch->old_name);
  
  	patchsize = parse_single_patch(state,
  				       buffer + offset + hdrsize,
  				       size - offset - hdrsize,
  				       patch);
  
  	if (patchsize < 0)
  		return -128;
  
  	if (!patchsize) {
  		static const char git_binary[] = "GIT binary patch\n";
  		int hd = hdrsize + offset;
  		unsigned long llen = linelen(buffer + hd, size - hd);
  
  		if (llen == sizeof(git_binary) - 1 &&
  		    !memcmp(git_binary, buffer + hd, llen)) {
  			int used;
  			state->linenr++;
  			used = parse_binary(state, buffer + hd + llen,
  					    size - hd - llen, patch);
  			if (used < 0)
  				return -1;
  			if (used)
  				patchsize = used + llen;
  			else
  				patchsize = 0;
  		}
  		else if (!memcmp(" differ\n", buffer + hd + llen - 8, 8)) {
  			static const char *binhdr[] = {
  				"Binary files ",
  				"Files ",
  				NULL,
  			};
  			int i;
  			for (i = 0; binhdr[i]; i++) {
  				int len = strlen(binhdr[i]);
  				if (len < size - hd &&
  				    !memcmp(binhdr[i], buffer + hd, len)) {
  					state->linenr++;
  					patch->is_binary = 1;
  					patchsize = llen;
  					break;
  				}
  			}
  		}
  
  		/* Empty patch cannot be applied if it is a text patch
  		 * without metadata change.  A binary patch appears
  		 * empty to us here.
  		 */
  		if ((state->apply || state->check) &&
  		    (!patch->is_binary && !metadata_changes(patch))) {
  			error(_("patch with only garbage at line %d"), state->linenr);
  			return -128;
  		}
  	}
  
  	return offset + hdrsize + patchsize;
  }
  
  static void reverse_patches(struct patch *p)
  {
  	for (; p; p = p->next) {
  		struct fragment *frag = p->fragments;
  
  		SWAP(p->new_name, p->old_name);
  		SWAP(p->new_mode, p->old_mode);
  		SWAP(p->is_new, p->is_delete);
  		SWAP(p->lines_added, p->lines_deleted);
  		SWAP(p->old_oid_prefix, p->new_oid_prefix);
  
  		for (; frag; frag = frag->next) {
  			SWAP(frag->newpos, frag->oldpos);
  			SWAP(frag->newlines, frag->oldlines);
  		}
  	}
  }
  
  static const char pluses[] =
  "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
  static const char minuses[]=
  "----------------------------------------------------------------------";
  
  static void show_stats(struct apply_state *state, struct patch *patch)
  {
  	struct strbuf qname = STRBUF_INIT;
  	char *cp = patch->new_name ? patch->new_name : patch->old_name;
  	int max, add, del;
  
  	quote_c_style(cp, &qname, NULL, 0);
  
  	/*
  	 * "scale" the filename
  	 */
  	max = state->max_len;
  	if (max > 50)
  		max = 50;
  
  	if (qname.len > max) {
  		cp = strchr(qname.buf + qname.len + 3 - max, '/');
  		if (!cp)
  			cp = qname.buf + qname.len + 3 - max;
  		strbuf_splice(&qname, 0, cp - qname.buf, "...", 3);
  	}
  
  	if (patch->is_binary) {
  		printf(" %-*s |  Bin\n", max, qname.buf);
  		strbuf_release(&qname);
  		return;
  	}
  
  	printf(" %-*s |", max, qname.buf);
  	strbuf_release(&qname);
  
  	/*
  	 * scale the add/delete
  	 */
  	max = max + state->max_change > 70 ? 70 - max : state->max_change;
  	add = patch->lines_added;
  	del = patch->lines_deleted;
  
  	if (state->max_change > 0) {
  		int total = ((add + del) * max + state->max_change / 2) / state->max_change;
  		add = (add * max + state->max_change / 2) / state->max_change;
  		del = total - add;
  	}
  	printf("%5d %.*s%.*s\n", patch->lines_added + patch->lines_deleted,
  		add, pluses, del, minuses);
  }
  
  static int read_old_data(struct stat *st, struct patch *patch,
  			 const char *path, struct strbuf *buf)
  {
  	int conv_flags = patch->crlf_in_old ?
  		CONV_EOL_KEEP_CRLF : CONV_EOL_RENORMALIZE;
  	switch (st->st_mode & S_IFMT) {
  	case S_IFLNK:
  		if (strbuf_readlink(buf, path, st->st_size) < 0)
  			return error(_("unable to read symlink %s"), path);
  		return 0;
  	case S_IFREG:
  		if (strbuf_read_file(buf, path, st->st_size) != st->st_size)
  			return error(_("unable to open or read %s"), path);
  		/*
  		 * "git apply" without "--index/--cached" should never look
  		 * at the index; the target file may not have been added to
  		 * the index yet, and we may not even be in any Git repository.
  		 * Pass NULL to convert_to_git() to stress this; the function
  		 * should never look at the index when explicit crlf option
  		 * is given.
  		 */
  		convert_to_git(NULL, path, buf->buf, buf->len, buf, conv_flags);
  		return 0;
  	default:
  		return -1;
  	}
  }
  
  /*
   * Update the preimage, and the common lines in postimage,
   * from buffer buf of length len. If postlen is 0 the postimage
   * is updated in place, otherwise it's updated on a new buffer
   * of length postlen
   */
  
  static void update_pre_post_images(struct image *preimage,
  				   struct image *postimage,
  				   char *buf,
  				   size_t len, size_t postlen)
  {
  	int i, ctx, reduced;
  	char *new_buf, *old_buf, *fixed;
  	struct image fixed_preimage;
  
  	/*
  	 * Update the preimage with whitespace fixes.  Note that we
  	 * are not losing preimage->buf -- apply_one_fragment() will
  	 * free "oldlines".
  	 */
  	prepare_image(&fixed_preimage, buf, len, 1);
  	assert(postlen
  	       ? fixed_preimage.nr == preimage->nr
  	       : fixed_preimage.nr <= preimage->nr);
  	for (i = 0; i < fixed_preimage.nr; i++)
  		fixed_preimage.line[i].flag = preimage->line[i].flag;
  	free(preimage->line_allocated);
  	*preimage = fixed_preimage;
  
  	/*
  	 * Adjust the common context lines in postimage. This can be
  	 * done in-place when we are shrinking it with whitespace
  	 * fixing, but needs a new buffer when ignoring whitespace or
  	 * expanding leading tabs to spaces.
  	 *
  	 * We trust the caller to tell us if the update can be done
  	 * in place (postlen==0) or not.
  	 */
  	old_buf = postimage->buf;
  	if (postlen)
  		new_buf = postimage->buf = xmalloc(postlen);
  	else
  		new_buf = old_buf;
  	fixed = preimage->buf;
  
  	for (i = reduced = ctx = 0; i < postimage->nr; i++) {
  		size_t l_len = postimage->line[i].len;
  		if (!(postimage->line[i].flag & LINE_COMMON)) {
  			/* an added line -- no counterparts in preimage */
  			memmove(new_buf, old_buf, l_len);
  			old_buf += l_len;
  			new_buf += l_len;
  			continue;
  		}
  
  		/* a common context -- skip it in the original postimage */
  		old_buf += l_len;
  
  		/* and find the corresponding one in the fixed preimage */
  		while (ctx < preimage->nr &&
  		       !(preimage->line[ctx].flag & LINE_COMMON)) {
  			fixed += preimage->line[ctx].len;
  			ctx++;
  		}
  
  		/*
  		 * preimage is expected to run out, if the caller
  		 * fixed addition of trailing blank lines.
  		 */
  		if (preimage->nr <= ctx) {
  			reduced++;
  			continue;
  		}
  
  		/* and copy it in, while fixing the line length */
  		l_len = preimage->line[ctx].len;
  		memcpy(new_buf, fixed, l_len);
  		new_buf += l_len;
  		fixed += l_len;
  		postimage->line[i].len = l_len;
  		ctx++;
  	}
  
  	if (postlen
  	    ? postlen < new_buf - postimage->buf
  	    : postimage->len < new_buf - postimage->buf)
  		BUG("caller miscounted postlen: asked %d, orig = %d, used = %d",
  		    (int)postlen, (int) postimage->len, (int)(new_buf - postimage->buf));
  
  	/* Fix the length of the whole thing */
  	postimage->len = new_buf - postimage->buf;
  	postimage->nr -= reduced;
  }
  
  static int line_by_line_fuzzy_match(struct image *img,
  				    struct image *preimage,
  				    struct image *postimage,
  				    unsigned long current,
  				    int current_lno,
  				    int preimage_limit)
  {
  	int i;
  	size_t imgoff = 0;
  	size_t preoff = 0;
  	size_t postlen = postimage->len;
  	size_t extra_chars;
  	char *buf;
  	char *preimage_eof;
  	char *preimage_end;
  	struct strbuf fixed;
  	char *fixed_buf;
  	size_t fixed_len;
  
  	for (i = 0; i < preimage_limit; i++) {
  		size_t prelen = preimage->line[i].len;
  		size_t imglen = img->line[current_lno+i].len;
  
  		if (!fuzzy_matchlines(img->buf + current + imgoff, imglen,
  				      preimage->buf + preoff, prelen))
  			return 0;
  		if (preimage->line[i].flag & LINE_COMMON)
  			postlen += imglen - prelen;
  		imgoff += imglen;
  		preoff += prelen;
  	}
  
  	/*
  	 * Ok, the preimage matches with whitespace fuzz.
  	 *
  	 * imgoff now holds the true length of the target that
  	 * matches the preimage before the end of the file.
  	 *
  	 * Count the number of characters in the preimage that fall
  	 * beyond the end of the file and make sure that all of them
  	 * are whitespace characters. (This can only happen if
  	 * we are removing blank lines at the end of the file.)
  	 */
  	buf = preimage_eof = preimage->buf + preoff;
  	for ( ; i < preimage->nr; i++)
  		preoff += preimage->line[i].len;
  	preimage_end = preimage->buf + preoff;
  	for ( ; buf < preimage_end; buf++)
  		if (!isspace(*buf))
  			return 0;
  
  	/*
  	 * Update the preimage and the common postimage context
  	 * lines to use the same whitespace as the target.
  	 * If whitespace is missing in the target (i.e.
  	 * if the preimage extends beyond the end of the file),
  	 * use the whitespace from the preimage.
  	 */
  	extra_chars = preimage_end - preimage_eof;
  	strbuf_init(&fixed, imgoff + extra_chars);
  	strbuf_add(&fixed, img->buf + current, imgoff);
  	strbuf_add(&fixed, preimage_eof, extra_chars);
  	fixed_buf = strbuf_detach(&fixed, &fixed_len);
  	update_pre_post_images(preimage, postimage,
  			       fixed_buf, fixed_len, postlen);
  	return 1;
  }
  
  static int match_fragment(struct apply_state *state,
  			  struct image *img,
  			  struct image *preimage,
  			  struct image *postimage,
  			  unsigned long current,
  			  int current_lno,
  			  unsigned ws_rule,
  			  int match_beginning, int match_end)
  {
  	int i;
  	char *fixed_buf, *buf, *orig, *target;
  	struct strbuf fixed;
  	size_t fixed_len, postlen;
  	int preimage_limit;
  
  	if (preimage->nr + current_lno <= img->nr) {
  		/*
  		 * The hunk falls within the boundaries of img.
  		 */
  		preimage_limit = preimage->nr;
  		if (match_end && (preimage->nr + current_lno != img->nr))
  			return 0;
  	} else if (state->ws_error_action == correct_ws_error &&
  		   (ws_rule & WS_BLANK_AT_EOF)) {
  		/*
  		 * This hunk extends beyond the end of img, and we are
  		 * removing blank lines at the end of the file.  This
  		 * many lines from the beginning of the preimage must
  		 * match with img, and the remainder of the preimage
  		 * must be blank.
  		 */
  		preimage_limit = img->nr - current_lno;
  	} else {
  		/*
  		 * The hunk extends beyond the end of the img and
  		 * we are not removing blanks at the end, so we
  		 * should reject the hunk at this position.
  		 */
  		return 0;
  	}
  
  	if (match_beginning && current_lno)
  		return 0;
  
  	/* Quick hash check */
  	for (i = 0; i < preimage_limit; i++)
  		if ((img->line[current_lno + i].flag & LINE_PATCHED) ||
  		    (preimage->line[i].hash != img->line[current_lno + i].hash))
  			return 0;
  
  	if (preimage_limit == preimage->nr) {
  		/*
  		 * Do we have an exact match?  If we were told to match
  		 * at the end, size must be exactly at current+fragsize,
  		 * otherwise current+fragsize must be still within the preimage,
  		 * and either case, the old piece should match the preimage
  		 * exactly.
  		 */
  		if ((match_end
  		     ? (current + preimage->len == img->len)
  		     : (current + preimage->len <= img->len)) &&
  		    !memcmp(img->buf + current, preimage->buf, preimage->len))
  			return 1;
  	} else {
  		/*
  		 * The preimage extends beyond the end of img, so
  		 * there cannot be an exact match.
  		 *
  		 * There must be one non-blank context line that match
  		 * a line before the end of img.
  		 */
  		char *buf_end;
  
  		buf = preimage->buf;
  		buf_end = buf;
  		for (i = 0; i < preimage_limit; i++)
  			buf_end += preimage->line[i].len;
  
  		for ( ; buf < buf_end; buf++)
  			if (!isspace(*buf))
  				break;
  		if (buf == buf_end)
  			return 0;
  	}
  
  	/*
  	 * No exact match. If we are ignoring whitespace, run a line-by-line
  	 * fuzzy matching. We collect all the line length information because
  	 * we need it to adjust whitespace if we match.
  	 */
  	if (state->ws_ignore_action == ignore_ws_change)
  		return line_by_line_fuzzy_match(img, preimage, postimage,
  						current, current_lno, preimage_limit);
  
  	if (state->ws_error_action != correct_ws_error)
  		return 0;
  
  	/*
  	 * The hunk does not apply byte-by-byte, but the hash says
  	 * it might with whitespace fuzz. We weren't asked to
  	 * ignore whitespace, we were asked to correct whitespace
  	 * errors, so let's try matching after whitespace correction.
  	 *
  	 * While checking the preimage against the target, whitespace
  	 * errors in both fixed, we count how large the corresponding
  	 * postimage needs to be.  The postimage prepared by
  	 * apply_one_fragment() has whitespace errors fixed on added
  	 * lines already, but the common lines were propagated as-is,
  	 * which may become longer when their whitespace errors are
  	 * fixed.
  	 */
  
  	/* First count added lines in postimage */
  	postlen = 0;
  	for (i = 0; i < postimage->nr; i++) {
  		if (!(postimage->line[i].flag & LINE_COMMON))
  			postlen += postimage->line[i].len;
  	}
  
  	/*
  	 * The preimage may extend beyond the end of the file,
  	 * but in this loop we will only handle the part of the
  	 * preimage that falls within the file.
  	 */
  	strbuf_init(&fixed, preimage->len + 1);
  	orig = preimage->buf;
  	target = img->buf + current;
  	for (i = 0; i < preimage_limit; i++) {
  		size_t oldlen = preimage->line[i].len;
  		size_t tgtlen = img->line[current_lno + i].len;
  		size_t fixstart = fixed.len;
  		struct strbuf tgtfix;
  		int match;
  
  		/* Try fixing the line in the preimage */
  		ws_fix_copy(&fixed, orig, oldlen, ws_rule, NULL);
  
  		/* Try fixing the line in the target */
  		strbuf_init(&tgtfix, tgtlen);
  		ws_fix_copy(&tgtfix, target, tgtlen, ws_rule, NULL);
  
  		/*
  		 * If they match, either the preimage was based on
  		 * a version before our tree fixed whitespace breakage,
  		 * or we are lacking a whitespace-fix patch the tree
  		 * the preimage was based on already had (i.e. target
  		 * has whitespace breakage, the preimage doesn't).
  		 * In either case, we are fixing the whitespace breakages
  		 * so we might as well take the fix together with their
  		 * real change.
  		 */
  		match = (tgtfix.len == fixed.len - fixstart &&
  			 !memcmp(tgtfix.buf, fixed.buf + fixstart,
  					     fixed.len - fixstart));
  
  		/* Add the length if this is common with the postimage */
  		if (preimage->line[i].flag & LINE_COMMON)
  			postlen += tgtfix.len;
  
  		strbuf_release(&tgtfix);
  		if (!match)
  			goto unmatch_exit;
  
  		orig += oldlen;
  		target += tgtlen;
  	}
  
  
  	/*
  	 * Now handle the lines in the preimage that falls beyond the
  	 * end of the file (if any). They will only match if they are
  	 * empty or only contain whitespace (if WS_BLANK_AT_EOL is
  	 * false).
  	 */
  	for ( ; i < preimage->nr; i++) {
  		size_t fixstart = fixed.len; /* start of the fixed preimage */
  		size_t oldlen = preimage->line[i].len;
  		int j;
  
  		/* Try fixing the line in the preimage */
  		ws_fix_copy(&fixed, orig, oldlen, ws_rule, NULL);
  
  		for (j = fixstart; j < fixed.len; j++)
  			if (!isspace(fixed.buf[j]))
  				goto unmatch_exit;
  
  		orig += oldlen;
  	}
  
  	/*
  	 * Yes, the preimage is based on an older version that still
  	 * has whitespace breakages unfixed, and fixing them makes the
  	 * hunk match.  Update the context lines in the postimage.
  	 */
  	fixed_buf = strbuf_detach(&fixed, &fixed_len);
  	if (postlen < postimage->len)
  		postlen = 0;
  	update_pre_post_images(preimage, postimage,
  			       fixed_buf, fixed_len, postlen);
  	return 1;
  
   unmatch_exit:
  	strbuf_release(&fixed);
  	return 0;
  }
  
  static int find_pos(struct apply_state *state,
  		    struct image *img,
  		    struct image *preimage,
  		    struct image *postimage,
  		    int line,
  		    unsigned ws_rule,
  		    int match_beginning, int match_end)
  {
  	int i;
  	unsigned long backwards, forwards, current;
  	int backwards_lno, forwards_lno, current_lno;
  
  	/*
  	 * If match_beginning or match_end is specified, there is no
  	 * point starting from a wrong line that will never match and
  	 * wander around and wait for a match at the specified end.
  	 */
  	if (match_beginning)
  		line = 0;
  	else if (match_end)
  		line = img->nr - preimage->nr;
  
  	/*
  	 * Because the comparison is unsigned, the following test
  	 * will also take care of a negative line number that can
  	 * result when match_end and preimage is larger than the target.
  	 */
  	if ((size_t) line > img->nr)
  		line = img->nr;
  
  	current = 0;
  	for (i = 0; i < line; i++)
  		current += img->line[i].len;
  
  	/*
  	 * There's probably some smart way to do this, but I'll leave
  	 * that to the smart and beautiful people. I'm simple and stupid.
  	 */
  	backwards = current;
  	backwards_lno = line;
  	forwards = current;
  	forwards_lno = line;
  	current_lno = line;
  
  	for (i = 0; ; i++) {
  		if (match_fragment(state, img, preimage, postimage,
  				   current, current_lno, ws_rule,
  				   match_beginning, match_end))
  			return current_lno;
  
  	again:
  		if (backwards_lno == 0 && forwards_lno == img->nr)
  			break;
  
  		if (i & 1) {
  			if (backwards_lno == 0) {
  				i++;
  				goto again;
  			}
  			backwards_lno--;
  			backwards -= img->line[backwards_lno].len;
  			current = backwards;
  			current_lno = backwards_lno;
  		} else {
  			if (forwards_lno == img->nr) {
  				i++;
  				goto again;
  			}
  			forwards += img->line[forwards_lno].len;
  			forwards_lno++;
  			current = forwards;
  			current_lno = forwards_lno;
  		}
  
  	}
  	return -1;
  }
  
  static void remove_first_line(struct image *img)
  {
  	img->buf += img->line[0].len;
  	img->len -= img->line[0].len;
  	img->line++;
  	img->nr--;
  }
  
  static void remove_last_line(struct image *img)
  {
  	img->len -= img->line[--img->nr].len;
  }
  
  /*
   * The change from "preimage" and "postimage" has been found to
   * apply at applied_pos (counts in line numbers) in "img".
   * Update "img" to remove "preimage" and replace it with "postimage".
   */
  static void update_image(struct apply_state *state,
  			 struct image *img,
  			 int applied_pos,
  			 struct image *preimage,
  			 struct image *postimage)
  {
  	/*
  	 * remove the copy of preimage at offset in img
  	 * and replace it with postimage
  	 */
  	int i, nr;
  	size_t remove_count, insert_count, applied_at = 0;
  	char *result;
  	int preimage_limit;
  
  	/*
  	 * If we are removing blank lines at the end of img,
  	 * the preimage may extend beyond the end.
  	 * If that is the case, we must be careful only to
  	 * remove the part of the preimage that falls within
  	 * the boundaries of img. Initialize preimage_limit
  	 * to the number of lines in the preimage that falls
  	 * within the boundaries.
  	 */
  	preimage_limit = preimage->nr;
  	if (preimage_limit > img->nr - applied_pos)
  		preimage_limit = img->nr - applied_pos;
  
  	for (i = 0; i < applied_pos; i++)
  		applied_at += img->line[i].len;
  
  	remove_count = 0;
  	for (i = 0; i < preimage_limit; i++)
  		remove_count += img->line[applied_pos + i].len;
  	insert_count = postimage->len;
  
  	/* Adjust the contents */
  	result = xmalloc(st_add3(st_sub(img->len, remove_count), insert_count, 1));
  	memcpy(result, img->buf, applied_at);
  	memcpy(result + applied_at, postimage->buf, postimage->len);
  	memcpy(result + applied_at + postimage->len,
  	       img->buf + (applied_at + remove_count),
  	       img->len - (applied_at + remove_count));
  	free(img->buf);
  	img->buf = result;
  	img->len += insert_count - remove_count;
  	result[img->len] = '\0';
  
  	/* Adjust the line table */
  	nr = img->nr + postimage->nr - preimage_limit;
  	if (preimage_limit < postimage->nr) {
  		/*
  		 * NOTE: this knows that we never call remove_first_line()
  		 * on anything other than pre/post image.
  		 */
  		REALLOC_ARRAY(img->line, nr);
  		img->line_allocated = img->line;
  	}
  	if (preimage_limit != postimage->nr)
  		MOVE_ARRAY(img->line + applied_pos + postimage->nr,
  			   img->line + applied_pos + preimage_limit,
  			   img->nr - (applied_pos + preimage_limit));
  	COPY_ARRAY(img->line + applied_pos, postimage->line, postimage->nr);
  	if (!state->allow_overlap)
  		for (i = 0; i < postimage->nr; i++)
  			img->line[applied_pos + i].flag |= LINE_PATCHED;
  	img->nr = nr;
  }
  
  /*
   * Use the patch-hunk text in "frag" to prepare two images (preimage and
   * postimage) for the hunk.  Find lines that match "preimage" in "img" and
   * replace the part of "img" with "postimage" text.
   */
  static int apply_one_fragment(struct apply_state *state,
  			      struct image *img, struct fragment *frag,
  			      int inaccurate_eof, unsigned ws_rule,
  			      int nth_fragment)
  {
  	int match_beginning, match_end;
  	const char *patch = frag->patch;
  	int size = frag->size;
  	char *old, *oldlines;
  	struct strbuf newlines;
  	int new_blank_lines_at_end = 0;
  	int found_new_blank_lines_at_end = 0;
  	int hunk_linenr = frag->linenr;
  	unsigned long leading, trailing;
  	int pos, applied_pos;
  	struct image preimage;
  	struct image postimage;
  
  	memset(&preimage, 0, sizeof(preimage));
  	memset(&postimage, 0, sizeof(postimage));
  	oldlines = xmalloc(size);
  	strbuf_init(&newlines, size);
  
  	old = oldlines;
  	while (size > 0) {
  		char first;
  		int len = linelen(patch, size);
  		int plen;
  		int added_blank_line = 0;
  		int is_blank_context = 0;
  		size_t start;
  
  		if (!len)
  			break;
  
  		/*
  		 * "plen" is how much of the line we should use for
  		 * the actual patch data. Normally we just remove the
  		 * first character on the line, but if the line is
  		 * followed by "\ No newline", then we also remove the
  		 * last one (which is the newline, of course).
  		 */
  		plen = len - 1;
  		if (len < size && patch[len] == '\\')
  			plen--;
  		first = *patch;
  		if (state->apply_in_reverse) {
  			if (first == '-')
  				first = '+';
  			else if (first == '+')
  				first = '-';
  		}
  
  		switch (first) {
  		case '\n':
  			/* Newer GNU diff, empty context line */
  			if (plen < 0)
  				/* ... followed by '\No newline'; nothing */
  				break;
  			*old++ = '\n';
  			strbuf_addch(&newlines, '\n');
  			add_line_info(&preimage, "\n", 1, LINE_COMMON);
  			add_line_info(&postimage, "\n", 1, LINE_COMMON);
  			is_blank_context = 1;
  			break;
  		case ' ':
  			if (plen && (ws_rule & WS_BLANK_AT_EOF) &&
  			    ws_blank_line(patch + 1, plen, ws_rule))
  				is_blank_context = 1;
  			/* fallthrough */
  		case '-':
  			memcpy(old, patch + 1, plen);
  			add_line_info(&preimage, old, plen,
  				      (first == ' ' ? LINE_COMMON : 0));
  			old += plen;
  			if (first == '-')
  				break;
  			/* fallthrough */
  		case '+':
  			/* --no-add does not add new lines */
  			if (first == '+' && state->no_add)
  				break;
  
  			start = newlines.len;
  			if (first != '+' ||
  			    !state->whitespace_error ||
  			    state->ws_error_action != correct_ws_error) {
  				strbuf_add(&newlines, patch + 1, plen);
  			}
  			else {
  				ws_fix_copy(&newlines, patch + 1, plen, ws_rule, &state->applied_after_fixing_ws);
  			}
  			add_line_info(&postimage, newlines.buf + start, newlines.len - start,
  				      (first == '+' ? 0 : LINE_COMMON));
  			if (first == '+' &&
  			    (ws_rule & WS_BLANK_AT_EOF) &&
  			    ws_blank_line(patch + 1, plen, ws_rule))
  				added_blank_line = 1;
  			break;
  		case '@': case '\\':
  			/* Ignore it, we already handled it */
  			break;
  		default:
  			if (state->apply_verbosity > verbosity_normal)
  				error(_("invalid start of line: '%c'"), first);
  			applied_pos = -1;
  			goto out;
  		}
  		if (added_blank_line) {
  			if (!new_blank_lines_at_end)
  				found_new_blank_lines_at_end = hunk_linenr;
  			new_blank_lines_at_end++;
  		}
  		else if (is_blank_context)
  			;
  		else
  			new_blank_lines_at_end = 0;
  		patch += len;
  		size -= len;
  		hunk_linenr++;
  	}
  	if (inaccurate_eof &&
  	    old > oldlines && old[-1] == '\n' &&
  	    newlines.len > 0 && newlines.buf[newlines.len - 1] == '\n') {
  		old--;
  		strbuf_setlen(&newlines, newlines.len - 1);
  		preimage.line_allocated[preimage.nr - 1].len--;
  		postimage.line_allocated[postimage.nr - 1].len--;
  	}
  
  	leading = frag->leading;
  	trailing = frag->trailing;
  
  	/*
  	 * A hunk to change lines at the beginning would begin with
  	 * @@ -1,L +N,M @@
  	 * but we need to be careful.  -U0 that inserts before the second
  	 * line also has this pattern.
  	 *
  	 * And a hunk to add to an empty file would begin with
  	 * @@ -0,0 +N,M @@
  	 *
  	 * In other words, a hunk that is (frag->oldpos <= 1) with or
  	 * without leading context must match at the beginning.
  	 */
  	match_beginning = (!frag->oldpos ||
  			   (frag->oldpos == 1 && !state->unidiff_zero));
  
  	/*
  	 * A hunk without trailing lines must match at the end.
  	 * However, we simply cannot tell if a hunk must match end
  	 * from the lack of trailing lines if the patch was generated
  	 * with unidiff without any context.
  	 */
  	match_end = !state->unidiff_zero && !trailing;
  
  	pos = frag->newpos ? (frag->newpos - 1) : 0;
  	preimage.buf = oldlines;
  	preimage.len = old - oldlines;
  	postimage.buf = newlines.buf;
  	postimage.len = newlines.len;
  	preimage.line = preimage.line_allocated;
  	postimage.line = postimage.line_allocated;
  
  	for (;;) {
  
  		applied_pos = find_pos(state, img, &preimage, &postimage, pos,
  				       ws_rule, match_beginning, match_end);
  
  		if (applied_pos >= 0)
  			break;
  
  		/* Am I at my context limits? */
  		if ((leading <= state->p_context) && (trailing <= state->p_context))
  			break;
  		if (match_beginning || match_end) {
  			match_beginning = match_end = 0;
  			continue;
  		}
  
  		/*
  		 * Reduce the number of context lines; reduce both
  		 * leading and trailing if they are equal otherwise
  		 * just reduce the larger context.
  		 */
  		if (leading >= trailing) {
  			remove_first_line(&preimage);
  			remove_first_line(&postimage);
  			pos--;
  			leading--;
  		}
  		if (trailing > leading) {
  			remove_last_line(&preimage);
  			remove_last_line(&postimage);
  			trailing--;
  		}
  	}
  
  	if (applied_pos >= 0) {
  		if (new_blank_lines_at_end &&
  		    preimage.nr + applied_pos >= img->nr &&
  		    (ws_rule & WS_BLANK_AT_EOF) &&
  		    state->ws_error_action != nowarn_ws_error) {
  			record_ws_error(state, WS_BLANK_AT_EOF, "+", 1,
  					found_new_blank_lines_at_end);
  			if (state->ws_error_action == correct_ws_error) {
  				while (new_blank_lines_at_end--)
  					remove_last_line(&postimage);
  			}
  			/*
  			 * We would want to prevent write_out_results()
  			 * from taking place in apply_patch() that follows
  			 * the callchain led us here, which is:
  			 * apply_patch->check_patch_list->check_patch->
  			 * apply_data->apply_fragments->apply_one_fragment
  			 */
  			if (state->ws_error_action == die_on_ws_error)
  				state->apply = 0;
  		}
  
  		if (state->apply_verbosity > verbosity_normal && applied_pos != pos) {
  			int offset = applied_pos - pos;
  			if (state->apply_in_reverse)
  				offset = 0 - offset;
  			fprintf_ln(stderr,
  				   Q_("Hunk #%d succeeded at %d (offset %d line).",
  				      "Hunk #%d succeeded at %d (offset %d lines).",
  				      offset),
  				   nth_fragment, applied_pos + 1, offset);
  		}
  
  		/*
  		 * Warn if it was necessary to reduce the number
  		 * of context lines.
  		 */
  		if ((leading != frag->leading ||
  		     trailing != frag->trailing) && state->apply_verbosity > verbosity_silent)
  			fprintf_ln(stderr, _("Context reduced to (%ld/%ld)"
  					     " to apply fragment at %d"),
  				   leading, trailing, applied_pos+1);
  		update_image(state, img, applied_pos, &preimage, &postimage);
  	} else {
  		if (state->apply_verbosity > verbosity_normal)
  			error(_("while searching for:\n%.*s"),
  			      (int)(old - oldlines), oldlines);
  	}
  
  out:
  	free(oldlines);
  	strbuf_release(&newlines);
  	free(preimage.line_allocated);
  	free(postimage.line_allocated);
  
  	return (applied_pos < 0);
  }
  
  static int apply_binary_fragment(struct apply_state *state,
  				 struct image *img,
  				 struct patch *patch)
  {
  	struct fragment *fragment = patch->fragments;
  	unsigned long len;
  	void *dst;
  
  	if (!fragment)
  		return error(_("missing binary patch data for '%s'"),
  			     patch->new_name ?
  			     patch->new_name :
  			     patch->old_name);
  
  	/* Binary patch is irreversible without the optional second hunk */
  	if (state->apply_in_reverse) {
  		if (!fragment->next)
  			return error(_("cannot reverse-apply a binary patch "
  				       "without the reverse hunk to '%s'"),
  				     patch->new_name
  				     ? patch->new_name : patch->old_name);
  		fragment = fragment->next;
  	}
  	switch (fragment->binary_patch_method) {
  	case BINARY_DELTA_DEFLATED:
  		dst = patch_delta(img->buf, img->len, fragment->patch,
  				  fragment->size, &len);
  		if (!dst)
  			return -1;
  		clear_image(img);
  		img->buf = dst;
  		img->len = len;
  		return 0;
  	case BINARY_LITERAL_DEFLATED:
  		clear_image(img);
  		img->len = fragment->size;
  		img->buf = xmemdupz(fragment->patch, img->len);
  		return 0;
  	}
  	return -1;
  }
  
  /*
   * Replace "img" with the result of applying the binary patch.
   * The binary patch data itself in patch->fragment is still kept
   * but the preimage prepared by the caller in "img" is freed here
   * or in the helper function apply_binary_fragment() this calls.
   */
  static int apply_binary(struct apply_state *state,
  			struct image *img,
  			struct patch *patch)
  {
  	const char *name = patch->old_name ? patch->old_name : patch->new_name;
  	struct object_id oid;
  	const unsigned hexsz = the_hash_algo->hexsz;
  
  	/*
  	 * For safety, we require patch index line to contain
  	 * full hex textual object ID for old and new, at least for now.
  	 */
  	if (strlen(patch->old_oid_prefix) != hexsz ||
  	    strlen(patch->new_oid_prefix) != hexsz ||
  	    get_oid_hex(patch->old_oid_prefix, &oid) ||
  	    get_oid_hex(patch->new_oid_prefix, &oid))
  		return error(_("cannot apply binary patch to '%s' "
  			       "without full index line"), name);
  
  	if (patch->old_name) {
  		/*
  		 * See if the old one matches what the patch
  		 * applies to.
  		 */
  		hash_object_file(img->buf, img->len, blob_type, &oid);
  		if (strcmp(oid_to_hex(&oid), patch->old_oid_prefix))
  			return error(_("the patch applies to '%s' (%s), "
  				       "which does not match the "
  				       "current contents."),
  				     name, oid_to_hex(&oid));
  	}
  	else {
  		/* Otherwise, the old one must be empty. */
  		if (img->len)
  			return error(_("the patch applies to an empty "
  				       "'%s' but it is not empty"), name);
  	}
  
  	get_oid_hex(patch->new_oid_prefix, &oid);
  	if (is_null_oid(&oid)) {
  		clear_image(img);
  		return 0; /* deletion patch */
  	}
  
  	if (has_object_file(&oid)) {
  		/* We already have the postimage */
  		enum object_type type;
  		unsigned long size;
  		char *result;
  
  		result = read_object_file(&oid, &type, &size);
  		if (!result)
  			return error(_("the necessary postimage %s for "
  				       "'%s' cannot be read"),
  				     patch->new_oid_prefix, name);
  		clear_image(img);
  		img->buf = result;
  		img->len = size;
  	} else {
  		/*
  		 * We have verified buf matches the preimage;
  		 * apply the patch data to it, which is stored
  		 * in the patch->fragments->{patch,size}.
  		 */
  		if (apply_binary_fragment(state, img, patch))
  			return error(_("binary patch does not apply to '%s'"),
  				     name);
  
  		/* verify that the result matches */
  		hash_object_file(img->buf, img->len, blob_type, &oid);
  		if (strcmp(oid_to_hex(&oid), patch->new_oid_prefix))
  			return error(_("binary patch to '%s' creates incorrect result (expecting %s, got %s)"),
  				name, patch->new_oid_prefix, oid_to_hex(&oid));
  	}
  
  	return 0;
  }
  
  static int apply_fragments(struct apply_state *state, struct image *img, struct patch *patch)
  {
  	struct fragment *frag = patch->fragments;
  	const char *name = patch->old_name ? patch->old_name : patch->new_name;
  	unsigned ws_rule = patch->ws_rule;
  	unsigned inaccurate_eof = patch->inaccurate_eof;
  	int nth = 0;
  
  	if (patch->is_binary)
  		return apply_binary(state, img, patch);
  
  	while (frag) {
  		nth++;
  		if (apply_one_fragment(state, img, frag, inaccurate_eof, ws_rule, nth)) {
  			error(_("patch failed: %s:%ld"), name, frag->oldpos);
  			if (!state->apply_with_reject)
  				return -1;
  			frag->rejected = 1;
  		}
  		frag = frag->next;
  	}
  	return 0;
  }
  
  static int read_blob_object(struct strbuf *buf, const struct object_id *oid, unsigned mode)
  {
  	if (S_ISGITLINK(mode)) {
  		strbuf_grow(buf, 100);
  		strbuf_addf(buf, "Subproject commit %s\n", oid_to_hex(oid));
  	} else {
  		enum object_type type;
  		unsigned long sz;
  		char *result;
  
  		result = read_object_file(oid, &type, &sz);
  		if (!result)
  			return -1;
  		/* XXX read_sha1_file NUL-terminates */
  		strbuf_attach(buf, result, sz, sz + 1);
  	}
  	return 0;
  }
  
  static int read_file_or_gitlink(const struct cache_entry *ce, struct strbuf *buf)
  {
  	if (!ce)
  		return 0;
  	return read_blob_object(buf, &ce->oid, ce->ce_mode);
  }
  
  static struct patch *in_fn_table(struct apply_state *state, const char *name)
  {
  	struct string_list_item *item;
  
  	if (name == NULL)
  		return NULL;
  
  	item = string_list_lookup(&state->fn_table, name);
  	if (item != NULL)
  		return (struct patch *)item->util;
  
  	return NULL;
  }
  
  /*
   * item->util in the filename table records the status of the path.
   * Usually it points at a patch (whose result records the contents
   * of it after applying it), but it could be PATH_WAS_DELETED for a
   * path that a previously applied patch has already removed, or
   * PATH_TO_BE_DELETED for a path that a later patch would remove.
   *
   * The latter is needed to deal with a case where two paths A and B
   * are swapped by first renaming A to B and then renaming B to A;
   * moving A to B should not be prevented due to presence of B as we
   * will remove it in a later patch.
   */
  #define PATH_TO_BE_DELETED ((struct patch *) -2)
  #define PATH_WAS_DELETED ((struct patch *) -1)
  
  static int to_be_deleted(struct patch *patch)
  {
  	return patch == PATH_TO_BE_DELETED;
  }
  
  static int was_deleted(struct patch *patch)
  {
  	return patch == PATH_WAS_DELETED;
  }
  
  static void add_to_fn_table(struct apply_state *state, struct patch *patch)
  {
  	struct string_list_item *item;
  
  	/*
  	 * Always add new_name unless patch is a deletion
  	 * This should cover the cases for normal diffs,
  	 * file creations and copies
  	 */
  	if (patch->new_name != NULL) {
  		item = string_list_insert(&state->fn_table, patch->new_name);
  		item->util = patch;
  	}
  
  	/*
  	 * store a failure on rename/deletion cases because
  	 * later chunks shouldn't patch old names
  	 */
  	if ((patch->new_name == NULL) || (patch->is_rename)) {
  		item = string_list_insert(&state->fn_table, patch->old_name);
  		item->util = PATH_WAS_DELETED;
  	}
  }
  
  static void prepare_fn_table(struct apply_state *state, struct patch *patch)
  {
  	/*
  	 * store information about incoming file deletion
  	 */
  	while (patch) {
  		if ((patch->new_name == NULL) || (patch->is_rename)) {
  			struct string_list_item *item;
  			item = string_list_insert(&state->fn_table, patch->old_name);
  			item->util = PATH_TO_BE_DELETED;
  		}
  		patch = patch->next;
  	}
  }
  
  static int checkout_target(struct index_state *istate,
  			   struct cache_entry *ce, struct stat *st)
  {
  	struct checkout costate = CHECKOUT_INIT;
  
  	costate.refresh_cache = 1;
  	costate.istate = istate;
  	if (checkout_entry(ce, &costate, NULL, NULL) ||
  	    lstat(ce->name, st))
  		return error(_("cannot checkout %s"), ce->name);
  	return 0;
  }
  
  static struct patch *previous_patch(struct apply_state *state,
  				    struct patch *patch,
  				    int *gone)
  {
  	struct patch *previous;
  
  	*gone = 0;
  	if (patch->is_copy || patch->is_rename)
  		return NULL; /* "git" patches do not depend on the order */
  
  	previous = in_fn_table(state, patch->old_name);
  	if (!previous)
  		return NULL;
  
  	if (to_be_deleted(previous))
  		return NULL; /* the deletion hasn't happened yet */
  
  	if (was_deleted(previous))
  		*gone = 1;
  
  	return previous;
  }
  
  static int verify_index_match(struct apply_state *state,
  			      const struct cache_entry *ce,
  			      struct stat *st)
  {
  	if (S_ISGITLINK(ce->ce_mode)) {
  		if (!S_ISDIR(st->st_mode))
  			return -1;
  		return 0;
  	}
  	return ie_match_stat(state->repo->index, ce, st,
  			     CE_MATCH_IGNORE_VALID | CE_MATCH_IGNORE_SKIP_WORKTREE);
  }
  
  #define SUBMODULE_PATCH_WITHOUT_INDEX 1
  
  static int load_patch_target(struct apply_state *state,
  			     struct strbuf *buf,
  			     const struct cache_entry *ce,
  			     struct stat *st,
  			     struct patch *patch,
  			     const char *name,
  			     unsigned expected_mode)
  {
  	if (state->cached || state->check_index) {
  		if (read_file_or_gitlink(ce, buf))
  			return error(_("failed to read %s"), name);
  	} else if (name) {
  		if (S_ISGITLINK(expected_mode)) {
  			if (ce)
  				return read_file_or_gitlink(ce, buf);
  			else
  				return SUBMODULE_PATCH_WITHOUT_INDEX;
  		} else if (has_symlink_leading_path(name, strlen(name))) {
  			return error(_("reading from '%s' beyond a symbolic link"), name);
  		} else {
  			if (read_old_data(st, patch, name, buf))
  				return error(_("failed to read %s"), name);
  		}
  	}
  	return 0;
  }
  
  /*
   * We are about to apply "patch"; populate the "image" with the
   * current version we have, from the working tree or from the index,
   * depending on the situation e.g. --cached/--index.  If we are
   * applying a non-git patch that incrementally updates the tree,
   * we read from the result of a previous diff.
   */
  static int load_preimage(struct apply_state *state,
  			 struct image *image,
  			 struct patch *patch, struct stat *st,
  			 const struct cache_entry *ce)
  {
  	struct strbuf buf = STRBUF_INIT;
  	size_t len;
  	char *img;
  	struct patch *previous;
  	int status;
  
  	previous = previous_patch(state, patch, &status);
  	if (status)
  		return error(_("path %s has been renamed/deleted"),
  			     patch->old_name);
  	if (previous) {
  		/* We have a patched copy in memory; use that. */
  		strbuf_add(&buf, previous->result, previous->resultsize);
  	} else {
  		status = load_patch_target(state, &buf, ce, st, patch,
  					   patch->old_name, patch->old_mode);
  		if (status < 0)
  			return status;
  		else if (status == SUBMODULE_PATCH_WITHOUT_INDEX) {
  			/*
  			 * There is no way to apply subproject
  			 * patch without looking at the index.
  			 * NEEDSWORK: shouldn't this be flagged
  			 * as an error???
  			 */
  			free_fragment_list(patch->fragments);
  			patch->fragments = NULL;
  		} else if (status) {
  			return error(_("failed to read %s"), patch->old_name);
  		}
  	}
  
  	img = strbuf_detach(&buf, &len);
  	prepare_image(image, img, len, !patch->is_binary);
  	return 0;
  }
  
  static int three_way_merge(struct apply_state *state,
  			   struct image *image,
  			   char *path,
  			   const struct object_id *base,
  			   const struct object_id *ours,
  			   const struct object_id *theirs)
  {
  	mmfile_t base_file, our_file, their_file;
  	mmbuffer_t result = { NULL };
  	int status;
  
  	read_mmblob(&base_file, base);
  	read_mmblob(&our_file, ours);
  	read_mmblob(&their_file, theirs);
  	status = ll_merge(&result, path,
  			  &base_file, "base",
  			  &our_file, "ours",
  			  &their_file, "theirs",
  			  state->repo->index,
  			  NULL);
  	free(base_file.ptr);
  	free(our_file.ptr);
  	free(their_file.ptr);
  	if (status < 0 || !result.ptr) {
  		free(result.ptr);
  		return -1;
  	}
  	clear_image(image);
  	image->buf = result.ptr;
  	image->len = result.size;
  
  	return status;
  }
  
  /*
   * When directly falling back to add/add three-way merge, we read from
   * the current contents of the new_name.  In no cases other than that
   * this function will be called.
   */
  static int load_current(struct apply_state *state,
  			struct image *image,
  			struct patch *patch)
  {
  	struct strbuf buf = STRBUF_INIT;
  	int status, pos;
  	size_t len;
  	char *img;
  	struct stat st;
  	struct cache_entry *ce;
  	char *name = patch->new_name;
  	unsigned mode = patch->new_mode;
  
  	if (!patch->is_new)
  		BUG("patch to %s is not a creation", patch->old_name);
  
  	pos = index_name_pos(state->repo->index, name, strlen(name));
  	if (pos < 0)
  		return error(_("%s: does not exist in index"), name);
  	ce = state->repo->index->cache[pos];
  	if (lstat(name, &st)) {
  		if (errno != ENOENT)
  			return error_errno("%s", name);
  		if (checkout_target(state->repo->index, ce, &st))
  			return -1;
  	}
  	if (verify_index_match(state, ce, &st))
  		return error(_("%s: does not match index"), name);
  
  	status = load_patch_target(state, &buf, ce, &st, patch, name, mode);
  	if (status < 0)
  		return status;
  	else if (status)
  		return -1;
  	img = strbuf_detach(&buf, &len);
  	prepare_image(image, img, len, !patch->is_binary);
  	return 0;
  }
  
  static int try_threeway(struct apply_state *state,
  			struct image *image,
  			struct patch *patch,
  			struct stat *st,
  			const struct cache_entry *ce)
  {
  	struct object_id pre_oid, post_oid, our_oid;
  	struct strbuf buf = STRBUF_INIT;
  	size_t len;
  	int status;
  	char *img;
  	struct image tmp_image;
  
  	/* No point falling back to 3-way merge in these cases */
  	if (patch->is_delete ||
  	    S_ISGITLINK(patch->old_mode) || S_ISGITLINK(patch->new_mode))
  		return -1;
  
  	/* Preimage the patch was prepared for */
  	if (patch->is_new)
  		write_object_file("", 0, blob_type, &pre_oid);
  	else if (get_oid(patch->old_oid_prefix, &pre_oid) ||
  		 read_blob_object(&buf, &pre_oid, patch->old_mode))
  		return error(_("repository lacks the necessary blob to fall back on 3-way merge."));
  
  	if (state->apply_verbosity > verbosity_silent)
  		fprintf(stderr, _("Falling back to three-way merge...\n"));
  
  	img = strbuf_detach(&buf, &len);
  	prepare_image(&tmp_image, img, len, 1);
  	/* Apply the patch to get the post image */
  	if (apply_fragments(state, &tmp_image, patch) < 0) {
  		clear_image(&tmp_image);
  		return -1;
  	}
  	/* post_oid is theirs */
  	write_object_file(tmp_image.buf, tmp_image.len, blob_type, &post_oid);
  	clear_image(&tmp_image);
  
  	/* our_oid is ours */
  	if (patch->is_new) {
  		if (load_current(state, &tmp_image, patch))
  			return error(_("cannot read the current contents of '%s'"),
  				     patch->new_name);
  	} else {
  		if (load_preimage(state, &tmp_image, patch, st, ce))
  			return error(_("cannot read the current contents of '%s'"),
  				     patch->old_name);
  	}
  	write_object_file(tmp_image.buf, tmp_image.len, blob_type, &our_oid);
  	clear_image(&tmp_image);
  
  	/* in-core three-way merge between post and our using pre as base */
  	status = three_way_merge(state, image, patch->new_name,
  				 &pre_oid, &our_oid, &post_oid);
  	if (status < 0) {
  		if (state->apply_verbosity > verbosity_silent)
  			fprintf(stderr,
  				_("Failed to fall back on three-way merge...\n"));
  		return status;
  	}
  
  	if (status) {
  		patch->conflicted_threeway = 1;
  		if (patch->is_new)
  			oidclr(&patch->threeway_stage[0]);
  		else
  			oidcpy(&patch->threeway_stage[0], &pre_oid);
  		oidcpy(&patch->threeway_stage[1], &our_oid);
  		oidcpy(&patch->threeway_stage[2], &post_oid);
  		if (state->apply_verbosity > verbosity_silent)
  			fprintf(stderr,
  				_("Applied patch to '%s' with conflicts.\n"),
  				patch->new_name);
  	} else {
  		if (state->apply_verbosity > verbosity_silent)
  			fprintf(stderr,
  				_("Applied patch to '%s' cleanly.\n"),
  				patch->new_name);
  	}
  	return 0;
  }
  
  static int apply_data(struct apply_state *state, struct patch *patch,
  		      struct stat *st, const struct cache_entry *ce)
  {
  	struct image image;
  
  	if (load_preimage(state, &image, patch, st, ce) < 0)
  		return -1;
  
  	if (patch->direct_to_threeway ||
  	    apply_fragments(state, &image, patch) < 0) {
  		/* Note: with --reject, apply_fragments() returns 0 */
  		if (!state->threeway || try_threeway(state, &image, patch, st, ce) < 0)
  			return -1;
  	}
  	patch->result = image.buf;
  	patch->resultsize = image.len;
  	add_to_fn_table(state, patch);
  	free(image.line_allocated);
  
  	if (0 < patch->is_delete && patch->resultsize)
  		return error(_("removal patch leaves file contents"));
  
  	return 0;
  }
  
  /*
   * If "patch" that we are looking at modifies or deletes what we have,
   * we would want it not to lose any local modification we have, either
   * in the working tree or in the index.
   *
   * This also decides if a non-git patch is a creation patch or a
   * modification to an existing empty file.  We do not check the state
   * of the current tree for a creation patch in this function; the caller
   * check_patch() separately makes sure (and errors out otherwise) that
   * the path the patch creates does not exist in the current tree.
   */
  static int check_preimage(struct apply_state *state,
  			  struct patch *patch,
  			  struct cache_entry **ce,
  			  struct stat *st)
  {
  	const char *old_name = patch->old_name;
  	struct patch *previous = NULL;
  	int stat_ret = 0, status;
  	unsigned st_mode = 0;
  
  	if (!old_name)
  		return 0;
  
  	assert(patch->is_new <= 0);
  	previous = previous_patch(state, patch, &status);
  
  	if (status)
  		return error(_("path %s has been renamed/deleted"), old_name);
  	if (previous) {
  		st_mode = previous->new_mode;
  	} else if (!state->cached) {
  		stat_ret = lstat(old_name, st);
  		if (stat_ret && errno != ENOENT)
  			return error_errno("%s", old_name);
  	}
  
  	if (state->check_index && !previous) {
  		int pos = index_name_pos(state->repo->index, old_name,
  					 strlen(old_name));
  		if (pos < 0) {
  			if (patch->is_new < 0)
  				goto is_new;
  			return error(_("%s: does not exist in index"), old_name);
  		}
  		*ce = state->repo->index->cache[pos];
  		if (stat_ret < 0) {
  			if (checkout_target(state->repo->index, *ce, st))
  				return -1;
  		}
  		if (!state->cached && verify_index_match(state, *ce, st))
  			return error(_("%s: does not match index"), old_name);
  		if (state->cached)
  			st_mode = (*ce)->ce_mode;
  	} else if (stat_ret < 0) {
  		if (patch->is_new < 0)
  			goto is_new;
  		return error_errno("%s", old_name);
  	}
  
  	if (!state->cached && !previous)
  		st_mode = ce_mode_from_stat(*ce, st->st_mode);
  
  	if (patch->is_new < 0)
  		patch->is_new = 0;
  	if (!patch->old_mode)
  		patch->old_mode = st_mode;
  	if ((st_mode ^ patch->old_mode) & S_IFMT)
  		return error(_("%s: wrong type"), old_name);
  	if (st_mode != patch->old_mode)
  		warning(_("%s has type %o, expected %o"),
  			old_name, st_mode, patch->old_mode);
  	if (!patch->new_mode && !patch->is_delete)
  		patch->new_mode = st_mode;
  	return 0;
  
   is_new:
  	patch->is_new = 1;
  	patch->is_delete = 0;
  	FREE_AND_NULL(patch->old_name);
  	return 0;
  }
  
  
  #define EXISTS_IN_INDEX 1
  #define EXISTS_IN_WORKTREE 2
  
  static int check_to_create(struct apply_state *state,
  			   const char *new_name,
  			   int ok_if_exists)
  {
  	struct stat nst;
  
  	if (state->check_index &&
  	    index_name_pos(state->repo->index, new_name, strlen(new_name)) >= 0 &&
  	    !ok_if_exists)
  		return EXISTS_IN_INDEX;
  	if (state->cached)
  		return 0;
  
  	if (!lstat(new_name, &nst)) {
  		if (S_ISDIR(nst.st_mode) || ok_if_exists)
  			return 0;
  		/*
  		 * A leading component of new_name might be a symlink
  		 * that is going to be removed with this patch, but
  		 * still pointing at somewhere that has the path.
  		 * In such a case, path "new_name" does not exist as
  		 * far as git is concerned.
  		 */
  		if (has_symlink_leading_path(new_name, strlen(new_name)))
  			return 0;
  
  		return EXISTS_IN_WORKTREE;
  	} else if (!is_missing_file_error(errno)) {
  		return error_errno("%s", new_name);
  	}
  	return 0;
  }
  
  static uintptr_t register_symlink_changes(struct apply_state *state,
  					  const char *path,
  					  uintptr_t what)
  {
  	struct string_list_item *ent;
  
  	ent = string_list_lookup(&state->symlink_changes, path);
  	if (!ent) {
  		ent = string_list_insert(&state->symlink_changes, path);
  		ent->util = (void *)0;
  	}
  	ent->util = (void *)(what | ((uintptr_t)ent->util));
  	return (uintptr_t)ent->util;
  }
  
  static uintptr_t check_symlink_changes(struct apply_state *state, const char *path)
  {
  	struct string_list_item *ent;
  
  	ent = string_list_lookup(&state->symlink_changes, path);
  	if (!ent)
  		return 0;
  	return (uintptr_t)ent->util;
  }
  
  static void prepare_symlink_changes(struct apply_state *state, struct patch *patch)
  {
  	for ( ; patch; patch = patch->next) {
  		if ((patch->old_name && S_ISLNK(patch->old_mode)) &&
  		    (patch->is_rename || patch->is_delete))
  			/* the symlink at patch->old_name is removed */
  			register_symlink_changes(state, patch->old_name, APPLY_SYMLINK_GOES_AWAY);
  
  		if (patch->new_name && S_ISLNK(patch->new_mode))
  			/* the symlink at patch->new_name is created or remains */
  			register_symlink_changes(state, patch->new_name, APPLY_SYMLINK_IN_RESULT);
  	}
  }
  
  static int path_is_beyond_symlink_1(struct apply_state *state, struct strbuf *name)
  {
  	do {
  		unsigned int change;
  
  		while (--name->len && name->buf[name->len] != '/')
  			; /* scan backwards */
  		if (!name->len)
  			break;
  		name->buf[name->len] = '\0';
  		change = check_symlink_changes(state, name->buf);
  		if (change & APPLY_SYMLINK_IN_RESULT)
  			return 1;
  		if (change & APPLY_SYMLINK_GOES_AWAY)
  			/*
  			 * This cannot be "return 0", because we may
  			 * see a new one created at a higher level.
  			 */
  			continue;
  
  		/* otherwise, check the preimage */
  		if (state->check_index) {
  			struct cache_entry *ce;
  
  			ce = index_file_exists(state->repo->index, name->buf,
  					       name->len, ignore_case);
  			if (ce && S_ISLNK(ce->ce_mode))
  				return 1;
  		} else {
  			struct stat st;
  			if (!lstat(name->buf, &st) && S_ISLNK(st.st_mode))
  				return 1;
  		}
  	} while (1);
  	return 0;
  }
  
  static int path_is_beyond_symlink(struct apply_state *state, const char *name_)
  {
  	int ret;
  	struct strbuf name = STRBUF_INIT;
  
  	assert(*name_ != '\0');
  	strbuf_addstr(&name, name_);
  	ret = path_is_beyond_symlink_1(state, &name);
  	strbuf_release(&name);
  
  	return ret;
  }
  
  static int check_unsafe_path(struct patch *patch)
  {
  	const char *old_name = NULL;
  	const char *new_name = NULL;
  	if (patch->is_delete)
  		old_name = patch->old_name;
  	else if (!patch->is_new && !patch->is_copy)
  		old_name = patch->old_name;
  	if (!patch->is_delete)
  		new_name = patch->new_name;
  
  	if (old_name && !verify_path(old_name, patch->old_mode))
  		return error(_("invalid path '%s'"), old_name);
  	if (new_name && !verify_path(new_name, patch->new_mode))
  		return error(_("invalid path '%s'"), new_name);
  	return 0;
  }
  
  /*
   * Check and apply the patch in-core; leave the result in patch->result
   * for the caller to write it out to the final destination.
   */
  static int check_patch(struct apply_state *state, struct patch *patch)
  {
  	struct stat st;
  	const char *old_name = patch->old_name;
  	const char *new_name = patch->new_name;
  	const char *name = old_name ? old_name : new_name;
  	struct cache_entry *ce = NULL;
  	struct patch *tpatch;
  	int ok_if_exists;
  	int status;
  
  	patch->rejected = 1; /* we will drop this after we succeed */
  
  	status = check_preimage(state, patch, &ce, &st);
  	if (status)
  		return status;
  	old_name = patch->old_name;
  
  	/*
  	 * A type-change diff is always split into a patch to delete
  	 * old, immediately followed by a patch to create new (see
  	 * diff.c::run_diff()); in such a case it is Ok that the entry
  	 * to be deleted by the previous patch is still in the working
  	 * tree and in the index.
  	 *
  	 * A patch to swap-rename between A and B would first rename A
  	 * to B and then rename B to A.  While applying the first one,
  	 * the presence of B should not stop A from getting renamed to
  	 * B; ask to_be_deleted() about the later rename.  Removal of
  	 * B and rename from A to B is handled the same way by asking
  	 * was_deleted().
  	 */
  	if ((tpatch = in_fn_table(state, new_name)) &&
  	    (was_deleted(tpatch) || to_be_deleted(tpatch)))
  		ok_if_exists = 1;
  	else
  		ok_if_exists = 0;
  
  	if (new_name &&
  	    ((0 < patch->is_new) || patch->is_rename || patch->is_copy)) {
  		int err = check_to_create(state, new_name, ok_if_exists);
  
  		if (err && state->threeway) {
  			patch->direct_to_threeway = 1;
  		} else switch (err) {
  		case 0:
  			break; /* happy */
  		case EXISTS_IN_INDEX:
  			return error(_("%s: already exists in index"), new_name);
  			break;
  		case EXISTS_IN_WORKTREE:
  			return error(_("%s: already exists in working directory"),
  				     new_name);
  		default:
  			return err;
  		}
  
  		if (!patch->new_mode) {
  			if (0 < patch->is_new)
  				patch->new_mode = S_IFREG | 0644;
  			else
  				patch->new_mode = patch->old_mode;
  		}
  	}
  
  	if (new_name && old_name) {
  		int same = !strcmp(old_name, new_name);
  		if (!patch->new_mode)
  			patch->new_mode = patch->old_mode;
  		if ((patch->old_mode ^ patch->new_mode) & S_IFMT) {
  			if (same)
  				return error(_("new mode (%o) of %s does not "
  					       "match old mode (%o)"),
  					patch->new_mode, new_name,
  					patch->old_mode);
  			else
  				return error(_("new mode (%o) of %s does not "
  					       "match old mode (%o) of %s"),
  					patch->new_mode, new_name,
  					patch->old_mode, old_name);
  		}
  	}
  
  	if (!state->unsafe_paths && check_unsafe_path(patch))
  		return -128;
  
  	/*
  	 * An attempt to read from or delete a path that is beyond a
  	 * symbolic link will be prevented by load_patch_target() that
  	 * is called at the beginning of apply_data() so we do not
  	 * have to worry about a patch marked with "is_delete" bit
  	 * here.  We however need to make sure that the patch result
  	 * is not deposited to a path that is beyond a symbolic link
  	 * here.
  	 */
  	if (!patch->is_delete && path_is_beyond_symlink(state, patch->new_name))
  		return error(_("affected file '%s' is beyond a symbolic link"),
  			     patch->new_name);
  
  	if (apply_data(state, patch, &st, ce) < 0)
  		return error(_("%s: patch does not apply"), name);
  	patch->rejected = 0;
  	return 0;
  }
  
  static int check_patch_list(struct apply_state *state, struct patch *patch)
  {
  	int err = 0;
  
  	prepare_symlink_changes(state, patch);
  	prepare_fn_table(state, patch);
  	while (patch) {
  		int res;
  		if (state->apply_verbosity > verbosity_normal)
  			say_patch_name(stderr,
  				       _("Checking patch %s..."), patch);
  		res = check_patch(state, patch);
  		if (res == -128)
  			return -128;
  		err |= res;
  		patch = patch->next;
  	}
  	return err;
  }
  
  static int read_apply_cache(struct apply_state *state)
  {
  	if (state->index_file)
  		return read_index_from(state->repo->index, state->index_file,
  				       get_git_dir());
  	else
  		return repo_read_index(state->repo);
  }
  
  /* This function tries to read the object name from the current index */
  static int get_current_oid(struct apply_state *state, const char *path,
  			   struct object_id *oid)
  {
  	int pos;
  
  	if (read_apply_cache(state) < 0)
  		return -1;
  	pos = index_name_pos(state->repo->index, path, strlen(path));
  	if (pos < 0)
  		return -1;
  	oidcpy(oid, &state->repo->index->cache[pos]->oid);
  	return 0;
  }
  
  static int preimage_oid_in_gitlink_patch(struct patch *p, struct object_id *oid)
  {
  	/*
  	 * A usable gitlink patch has only one fragment (hunk) that looks like:
  	 * @@ -1 +1 @@
  	 * -Subproject commit <old sha1>
  	 * +Subproject commit <new sha1>
  	 * or
  	 * @@ -1 +0,0 @@
  	 * -Subproject commit <old sha1>
  	 * for a removal patch.
  	 */
  	struct fragment *hunk = p->fragments;
  	static const char heading[] = "-Subproject commit ";
  	char *preimage;
  
  	if (/* does the patch have only one hunk? */
  	    hunk && !hunk->next &&
  	    /* is its preimage one line? */
  	    hunk->oldpos == 1 && hunk->oldlines == 1 &&
  	    /* does preimage begin with the heading? */
  	    (preimage = memchr(hunk->patch, '\n', hunk->size)) != NULL &&
  	    starts_with(++preimage, heading) &&
  	    /* does it record full SHA-1? */
  	    !get_oid_hex(preimage + sizeof(heading) - 1, oid) &&
  	    preimage[sizeof(heading) + the_hash_algo->hexsz - 1] == '\n' &&
  	    /* does the abbreviated name on the index line agree with it? */
  	    starts_with(preimage + sizeof(heading) - 1, p->old_oid_prefix))
  		return 0; /* it all looks fine */
  
  	/* we may have full object name on the index line */
  	return get_oid_hex(p->old_oid_prefix, oid);
  }
  
  /* Build an index that contains just the files needed for a 3way merge */
  static int build_fake_ancestor(struct apply_state *state, struct patch *list)
  {
  	struct patch *patch;
  	struct index_state result = { NULL };
  	struct lock_file lock = LOCK_INIT;
  	int res;
  
  	/* Once we start supporting the reverse patch, it may be
  	 * worth showing the new sha1 prefix, but until then...
  	 */
  	for (patch = list; patch; patch = patch->next) {
  		struct object_id oid;
  		struct cache_entry *ce;
  		const char *name;
  
  		name = patch->old_name ? patch->old_name : patch->new_name;
  		if (0 < patch->is_new)
  			continue;
  
  		if (S_ISGITLINK(patch->old_mode)) {
  			if (!preimage_oid_in_gitlink_patch(patch, &oid))
  				; /* ok, the textual part looks sane */
  			else
  				return error(_("sha1 information is lacking or "
  					       "useless for submodule %s"), name);
  		} else if (!get_oid_blob(patch->old_oid_prefix, &oid)) {
  			; /* ok */
  		} else if (!patch->lines_added && !patch->lines_deleted) {
  			/* mode-only change: update the current */
  			if (get_current_oid(state, patch->old_name, &oid))
  				return error(_("mode change for %s, which is not "
  					       "in current HEAD"), name);
  		} else
  			return error(_("sha1 information is lacking or useless "
  				       "(%s)."), name);
  
  		ce = make_cache_entry(&result, patch->old_mode, &oid, name, 0, 0);
  		if (!ce)
  			return error(_("make_cache_entry failed for path '%s'"),
  				     name);
  		if (add_index_entry(&result, ce, ADD_CACHE_OK_TO_ADD)) {
  			discard_cache_entry(ce);
  			return error(_("could not add %s to temporary index"),
  				     name);
  		}
  	}
  
  	hold_lock_file_for_update(&lock, state->fake_ancestor, LOCK_DIE_ON_ERROR);
  	res = write_locked_index(&result, &lock, COMMIT_LOCK);
  	discard_index(&result);
  
  	if (res)
  		return error(_("could not write temporary index to %s"),
  			     state->fake_ancestor);
  
  	return 0;
  }
  
  static void stat_patch_list(struct apply_state *state, struct patch *patch)
  {
  	int files, adds, dels;
  
  	for (files = adds = dels = 0 ; patch ; patch = patch->next) {
  		files++;
  		adds += patch->lines_added;
  		dels += patch->lines_deleted;
  		show_stats(state, patch);
  	}
  
  	print_stat_summary(stdout, files, adds, dels);
  }
  
  static void numstat_patch_list(struct apply_state *state,
  			       struct patch *patch)
  {
  	for ( ; patch; patch = patch->next) {
  		const char *name;
  		name = patch->new_name ? patch->new_name : patch->old_name;
  		if (patch->is_binary)
  			printf("-\t-\t");
  		else
  			printf("%d\t%d\t", patch->lines_added, patch->lines_deleted);
  		write_name_quoted(name, stdout, state->line_termination);
  	}
  }
  
  static void show_file_mode_name(const char *newdelete, unsigned int mode, const char *name)
  {
  	if (mode)
  		printf(" %s mode %06o %s\n", newdelete, mode, name);
  	else
  		printf(" %s %s\n", newdelete, name);
  }
  
  static void show_mode_change(struct patch *p, int show_name)
  {
  	if (p->old_mode && p->new_mode && p->old_mode != p->new_mode) {
  		if (show_name)
  			printf(" mode change %06o => %06o %s\n",
  			       p->old_mode, p->new_mode, p->new_name);
  		else
  			printf(" mode change %06o => %06o\n",
  			       p->old_mode, p->new_mode);
  	}
  }
  
  static void show_rename_copy(struct patch *p)
  {
  	const char *renamecopy = p->is_rename ? "rename" : "copy";
  	const char *old_name, *new_name;
  
  	/* Find common prefix */
  	old_name = p->old_name;
  	new_name = p->new_name;
  	while (1) {
  		const char *slash_old, *slash_new;
  		slash_old = strchr(old_name, '/');
  		slash_new = strchr(new_name, '/');
  		if (!slash_old ||
  		    !slash_new ||
  		    slash_old - old_name != slash_new - new_name ||
  		    memcmp(old_name, new_name, slash_new - new_name))
  			break;
  		old_name = slash_old + 1;
  		new_name = slash_new + 1;
  	}
  	/* p->old_name thru old_name is the common prefix, and old_name and new_name
  	 * through the end of names are renames
  	 */
  	if (old_name != p->old_name)
  		printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
  		       (int)(old_name - p->old_name), p->old_name,
  		       old_name, new_name, p->score);
  	else
  		printf(" %s %s => %s (%d%%)\n", renamecopy,
  		       p->old_name, p->new_name, p->score);
  	show_mode_change(p, 0);
  }
  
  static void summary_patch_list(struct patch *patch)
  {
  	struct patch *p;
  
  	for (p = patch; p; p = p->next) {
  		if (p->is_new)
  			show_file_mode_name("create", p->new_mode, p->new_name);
  		else if (p->is_delete)
  			show_file_mode_name("delete", p->old_mode, p->old_name);
  		else {
  			if (p->is_rename || p->is_copy)
  				show_rename_copy(p);
  			else {
  				if (p->score) {
  					printf(" rewrite %s (%d%%)\n",
  					       p->new_name, p->score);
  					show_mode_change(p, 0);
  				}
  				else
  					show_mode_change(p, 1);
  			}
  		}
  	}
  }
  
  static void patch_stats(struct apply_state *state, struct patch *patch)
  {
  	int lines = patch->lines_added + patch->lines_deleted;
  
  	if (lines > state->max_change)
  		state->max_change = lines;
  	if (patch->old_name) {
  		int len = quote_c_style(patch->old_name, NULL, NULL, 0);
  		if (!len)
  			len = strlen(patch->old_name);
  		if (len > state->max_len)
  			state->max_len = len;
  	}
  	if (patch->new_name) {
  		int len = quote_c_style(patch->new_name, NULL, NULL, 0);
  		if (!len)
  			len = strlen(patch->new_name);
  		if (len > state->max_len)
  			state->max_len = len;
  	}
  }
  
  static int remove_file(struct apply_state *state, struct patch *patch, int rmdir_empty)
  {
  	if (state->update_index && !state->ita_only) {
  		if (remove_file_from_index(state->repo->index, patch->old_name) < 0)
  			return error(_("unable to remove %s from index"), patch->old_name);
  	}
  	if (!state->cached) {
  		if (!remove_or_warn(patch->old_mode, patch->old_name) && rmdir_empty) {
  			remove_path(patch->old_name);
  		}
  	}
  	return 0;
  }
  
  static int add_index_file(struct apply_state *state,
  			  const char *path,
  			  unsigned mode,
  			  void *buf,
  			  unsigned long size)
  {
  	struct stat st;
  	struct cache_entry *ce;
  	int namelen = strlen(path);
  
  	ce = make_empty_cache_entry(state->repo->index, namelen);
  	memcpy(ce->name, path, namelen);
  	ce->ce_mode = create_ce_mode(mode);
  	ce->ce_flags = create_ce_flags(0);
  	ce->ce_namelen = namelen;
  	if (state->ita_only) {
  		ce->ce_flags |= CE_INTENT_TO_ADD;
  		set_object_name_for_intent_to_add_entry(ce);
  	} else if (S_ISGITLINK(mode)) {
  		const char *s;
  
  		if (!skip_prefix(buf, "Subproject commit ", &s) ||
  		    get_oid_hex(s, &ce->oid)) {
  			discard_cache_entry(ce);
  			return error(_("corrupt patch for submodule %s"), path);
  		}
  	} else {
  		if (!state->cached) {
  			if (lstat(path, &st) < 0) {
  				discard_cache_entry(ce);
  				return error_errno(_("unable to stat newly "
  						     "created file '%s'"),
  						   path);
  			}
  			fill_stat_cache_info(state->repo->index, ce, &st);
  		}
  		if (write_object_file(buf, size, blob_type, &ce->oid) < 0) {
  			discard_cache_entry(ce);
  			return error(_("unable to create backing store "
  				       "for newly created file %s"), path);
  		}
  	}
  	if (add_index_entry(state->repo->index, ce, ADD_CACHE_OK_TO_ADD) < 0) {
  		discard_cache_entry(ce);
  		return error(_("unable to add cache entry for %s"), path);
  	}
  
  	return 0;
  }
  
  /*
   * Returns:
   *  -1 if an unrecoverable error happened
   *   0 if everything went well
   *   1 if a recoverable error happened
   */
  static int try_create_file(struct apply_state *state, const char *path,
  			   unsigned int mode, const char *buf,
  			   unsigned long size)
  {
  	int fd, res;
  	struct strbuf nbuf = STRBUF_INIT;
  
  	if (S_ISGITLINK(mode)) {
  		struct stat st;
  		if (!lstat(path, &st) && S_ISDIR(st.st_mode))
  			return 0;
  		return !!mkdir(path, 0777);
  	}
  
  	if (has_symlinks && S_ISLNK(mode))
  		/* Although buf:size is counted string, it also is NUL
  		 * terminated.
  		 */
  		return !!symlink(buf, path);
  
  	fd = open(path, O_CREAT | O_EXCL | O_WRONLY, (mode & 0100) ? 0777 : 0666);
  	if (fd < 0)
  		return 1;
  
  	if (convert_to_working_tree(state->repo->index, path, buf, size, &nbuf)) {
  		size = nbuf.len;
  		buf  = nbuf.buf;
  	}
  
  	res = write_in_full(fd, buf, size) < 0;
  	if (res)
  		error_errno(_("failed to write to '%s'"), path);
  	strbuf_release(&nbuf);
  
  	if (close(fd) < 0 && !res)
  		return error_errno(_("closing file '%s'"), path);
  
  	return res ? -1 : 0;
  }
  
  /*
   * We optimistically assume that the directories exist,
   * which is true 99% of the time anyway. If they don't,
   * we create them and try again.
   *
   * Returns:
   *   -1 on error
   *   0 otherwise
   */
  static int create_one_file(struct apply_state *state,
  			   char *path,
  			   unsigned mode,
  			   const char *buf,
  			   unsigned long size)
  {
  	int res;
  
  	if (state->cached)
  		return 0;
  
  	res = try_create_file(state, path, mode, buf, size);
  	if (res < 0)
  		return -1;
  	if (!res)
  		return 0;
  
  	if (errno == ENOENT) {
  		if (safe_create_leading_directories(path))
  			return 0;
  		res = try_create_file(state, path, mode, buf, size);
  		if (res < 0)
  			return -1;
  		if (!res)
  			return 0;
  	}
  
  	if (errno == EEXIST || errno == EACCES) {
  		/* We may be trying to create a file where a directory
  		 * used to be.
  		 */
  		struct stat st;
  		if (!lstat(path, &st) && (!S_ISDIR(st.st_mode) || !rmdir(path)))
  			errno = EEXIST;
  	}
  
  	if (errno == EEXIST) {
  		unsigned int nr = getpid();
  
  		for (;;) {
  			char newpath[PATH_MAX];
  			mksnpath(newpath, sizeof(newpath), "%s~%u", path, nr);
  			res = try_create_file(state, newpath, mode, buf, size);
  			if (res < 0)
  				return -1;
  			if (!res) {
  				if (!rename(newpath, path))
  					return 0;
  				unlink_or_warn(newpath);
  				break;
  			}
  			if (errno != EEXIST)
  				break;
  			++nr;
  		}
  	}
  	return error_errno(_("unable to write file '%s' mode %o"),
  			   path, mode);
  }
  
  static int add_conflicted_stages_file(struct apply_state *state,
  				       struct patch *patch)
  {
  	int stage, namelen;
  	unsigned mode;
  	struct cache_entry *ce;
  
  	if (!state->update_index)
  		return 0;
  	namelen = strlen(patch->new_name);
  	mode = patch->new_mode ? patch->new_mode : (S_IFREG | 0644);
  
  	remove_file_from_index(state->repo->index, patch->new_name);
  	for (stage = 1; stage < 4; stage++) {
  		if (is_null_oid(&patch->threeway_stage[stage - 1]))
  			continue;
  		ce = make_empty_cache_entry(state->repo->index, namelen);
  		memcpy(ce->name, patch->new_name, namelen);
  		ce->ce_mode = create_ce_mode(mode);
  		ce->ce_flags = create_ce_flags(stage);
  		ce->ce_namelen = namelen;
  		oidcpy(&ce->oid, &patch->threeway_stage[stage - 1]);
  		if (add_index_entry(state->repo->index, ce, ADD_CACHE_OK_TO_ADD) < 0) {
  			discard_cache_entry(ce);
  			return error(_("unable to add cache entry for %s"),
  				     patch->new_name);
  		}
  	}
  
  	return 0;
  }
  
  static int create_file(struct apply_state *state, struct patch *patch)
  {
  	char *path = patch->new_name;
  	unsigned mode = patch->new_mode;
  	unsigned long size = patch->resultsize;
  	char *buf = patch->result;
  
  	if (!mode)
  		mode = S_IFREG | 0644;
  	if (create_one_file(state, path, mode, buf, size))
  		return -1;
  
  	if (patch->conflicted_threeway)
  		return add_conflicted_stages_file(state, patch);
  	else if (state->update_index)
  		return add_index_file(state, path, mode, buf, size);
  	return 0;
  }
  
  /* phase zero is to remove, phase one is to create */
  static int write_out_one_result(struct apply_state *state,
  				struct patch *patch,
  				int phase)
  {
  	if (patch->is_delete > 0) {
  		if (phase == 0)
  			return remove_file(state, patch, 1);
  		return 0;
  	}
  	if (patch->is_new > 0 || patch->is_copy) {
  		if (phase == 1)
  			return create_file(state, patch);
  		return 0;
  	}
  	/*
  	 * Rename or modification boils down to the same
  	 * thing: remove the old, write the new
  	 */
  	if (phase == 0)
  		return remove_file(state, patch, patch->is_rename);
  	if (phase == 1)
  		return create_file(state, patch);
  	return 0;
  }
  
  static int write_out_one_reject(struct apply_state *state, struct patch *patch)
  {
  	FILE *rej;
  	char namebuf[PATH_MAX];
  	struct fragment *frag;
  	int cnt = 0;
  	struct strbuf sb = STRBUF_INIT;
  
  	for (cnt = 0, frag = patch->fragments; frag; frag = frag->next) {
  		if (!frag->rejected)
  			continue;
  		cnt++;
  	}
  
  	if (!cnt) {
  		if (state->apply_verbosity > verbosity_normal)
  			say_patch_name(stderr,
  				       _("Applied patch %s cleanly."), patch);
  		return 0;
  	}
  
  	/* This should not happen, because a removal patch that leaves
  	 * contents are marked "rejected" at the patch level.
  	 */
  	if (!patch->new_name)
  		die(_("internal error"));
  
  	/* Say this even without --verbose */
  	strbuf_addf(&sb, Q_("Applying patch %%s with %d reject...",
  			    "Applying patch %%s with %d rejects...",
  			    cnt),
  		    cnt);
  	if (state->apply_verbosity > verbosity_silent)
  		say_patch_name(stderr, sb.buf, patch);
  	strbuf_release(&sb);
  
  	cnt = strlen(patch->new_name);
  	if (ARRAY_SIZE(namebuf) <= cnt + 5) {
  		cnt = ARRAY_SIZE(namebuf) - 5;
  		warning(_("truncating .rej filename to %.*s.rej"),
  			cnt - 1, patch->new_name);
  	}
  	memcpy(namebuf, patch->new_name, cnt);
  	memcpy(namebuf + cnt, ".rej", 5);
  
  	rej = fopen(namebuf, "w");
  	if (!rej)
  		return error_errno(_("cannot open %s"), namebuf);
  
  	/* Normal git tools never deal with .rej, so do not pretend
  	 * this is a git patch by saying --git or giving extended
  	 * headers.  While at it, maybe please "kompare" that wants
  	 * the trailing TAB and some garbage at the end of line ;-).
  	 */
  	fprintf(rej, "diff a/%s b/%s\t(rejected hunks)\n",
  		patch->new_name, patch->new_name);
  	for (cnt = 1, frag = patch->fragments;
  	     frag;
  	     cnt++, frag = frag->next) {
  		if (!frag->rejected) {
  			if (state->apply_verbosity > verbosity_silent)
  				fprintf_ln(stderr, _("Hunk #%d applied cleanly."), cnt);
  			continue;
  		}
  		if (state->apply_verbosity > verbosity_silent)
  			fprintf_ln(stderr, _("Rejected hunk #%d."), cnt);
  		fprintf(rej, "%.*s", frag->size, frag->patch);
  		if (frag->patch[frag->size-1] != '\n')
  			fputc('\n', rej);
  	}
  	fclose(rej);
  	return -1;
  }
  
  /*
   * Returns:
   *  -1 if an error happened
   *   0 if the patch applied cleanly
   *   1 if the patch did not apply cleanly
   */
  static int write_out_results(struct apply_state *state, struct patch *list)
  {
  	int phase;
  	int errs = 0;
  	struct patch *l;
  	struct string_list cpath = STRING_LIST_INIT_DUP;
  
  	for (phase = 0; phase < 2; phase++) {
  		l = list;
  		while (l) {
  			if (l->rejected)
  				errs = 1;
  			else {
  				if (write_out_one_result(state, l, phase)) {
  					string_list_clear(&cpath, 0);
  					return -1;
  				}
  				if (phase == 1) {
  					if (write_out_one_reject(state, l))
  						errs = 1;
  					if (l->conflicted_threeway) {
  						string_list_append(&cpath, l->new_name);
  						errs = 1;
  					}
  				}
  			}
  			l = l->next;
  		}
  	}
  
  	if (cpath.nr) {
  		struct string_list_item *item;
  
  		string_list_sort(&cpath);
  		if (state->apply_verbosity > verbosity_silent) {
  			for_each_string_list_item(item, &cpath)
  				fprintf(stderr, "U %s\n", item->string);
  		}
  		string_list_clear(&cpath, 0);
  
  		repo_rerere(state->repo, 0);
  	}
  
  	return errs;
  }
  
  /*
   * Try to apply a patch.
   *
   * Returns:
   *  -128 if a bad error happened (like patch unreadable)
   *  -1 if patch did not apply and user cannot deal with it
   *   0 if the patch applied
   *   1 if the patch did not apply but user might fix it
   */
  static int apply_patch(struct apply_state *state,
  		       int fd,
  		       const char *filename,
  		       int options)
  {
  	size_t offset;
  	struct strbuf buf = STRBUF_INIT; /* owns the patch text */
  	struct patch *list = NULL, **listp = &list;
  	int skipped_patch = 0;
  	int res = 0;
  
  	state->patch_input_file = filename;
  	if (read_patch_file(&buf, fd) < 0)
  		return -128;
  	offset = 0;
  	while (offset < buf.len) {
  		struct patch *patch;
  		int nr;
  
  		patch = xcalloc(1, sizeof(*patch));
  		patch->inaccurate_eof = !!(options & APPLY_OPT_INACCURATE_EOF);
  		patch->recount =  !!(options & APPLY_OPT_RECOUNT);
  		nr = parse_chunk(state, buf.buf + offset, buf.len - offset, patch);
  		if (nr < 0) {
  			free_patch(patch);
  			if (nr == -128) {
  				res = -128;
  				goto end;
  			}
  			break;
  		}
  		if (state->apply_in_reverse)
  			reverse_patches(patch);
  		if (use_patch(state, patch)) {
  			patch_stats(state, patch);
  			*listp = patch;
  			listp = &patch->next;
  		}
  		else {
  			if (state->apply_verbosity > verbosity_normal)
  				say_patch_name(stderr, _("Skipped patch '%s'."), patch);
  			free_patch(patch);
  			skipped_patch++;
  		}
  		offset += nr;
  	}
  
  	if (!list && !skipped_patch) {
  		error(_("unrecognized input"));
  		res = -128;
  		goto end;
  	}
  
  	if (state->whitespace_error && (state->ws_error_action == die_on_ws_error))
  		state->apply = 0;
  
  	state->update_index = (state->check_index || state->ita_only) && state->apply;
  	if (state->update_index && !is_lock_file_locked(&state->lock_file)) {
  		if (state->index_file)
  			hold_lock_file_for_update(&state->lock_file,
  						  state->index_file,
  						  LOCK_DIE_ON_ERROR);
  		else
  			repo_hold_locked_index(state->repo, &state->lock_file,
  					       LOCK_DIE_ON_ERROR);
  	}
  
  	if (state->check_index && read_apply_cache(state) < 0) {
  		error(_("unable to read index file"));
  		res = -128;
  		goto end;
  	}
  
  	if (state->check || state->apply) {
  		int r = check_patch_list(state, list);
  		if (r == -128) {
  			res = -128;
  			goto end;
  		}
  		if (r < 0 && !state->apply_with_reject) {
  			res = -1;
  			goto end;
  		}
  	}
  
  	if (state->apply) {
  		int write_res = write_out_results(state, list);
  		if (write_res < 0) {
  			res = -128;
  			goto end;
  		}
  		if (write_res > 0) {
  			/* with --3way, we still need to write the index out */
  			res = state->apply_with_reject ? -1 : 1;
  			goto end;
  		}
  	}
  
  	if (state->fake_ancestor &&
  	    build_fake_ancestor(state, list)) {
  		res = -128;
  		goto end;
  	}
  
  	if (state->diffstat && state->apply_verbosity > verbosity_silent)
  		stat_patch_list(state, list);
  
  	if (state->numstat && state->apply_verbosity > verbosity_silent)
  		numstat_patch_list(state, list);
  
  	if (state->summary && state->apply_verbosity > verbosity_silent)
  		summary_patch_list(list);
  
  end:
  	free_patch_list(list);
  	strbuf_release(&buf);
  	string_list_clear(&state->fn_table, 0);
  	return res;
  }
  
  static int apply_option_parse_exclude(const struct option *opt,
  				      const char *arg, int unset)
  {
  	struct apply_state *state = opt->value;
  
  	BUG_ON_OPT_NEG(unset);
  
  	add_name_limit(state, arg, 1);
  	return 0;
  }
  
  static int apply_option_parse_include(const struct option *opt,
  				      const char *arg, int unset)
  {
  	struct apply_state *state = opt->value;
  
  	BUG_ON_OPT_NEG(unset);
  
  	add_name_limit(state, arg, 0);
  	state->has_include = 1;
  	return 0;
  }
  
  static int apply_option_parse_p(const struct option *opt,
  				const char *arg,
  				int unset)
  {
  	struct apply_state *state = opt->value;
  
  	BUG_ON_OPT_NEG(unset);
  
  	state->p_value = atoi(arg);
  	state->p_value_known = 1;
  	return 0;
  }
  
  static int apply_option_parse_space_change(const struct option *opt,
  					   const char *arg, int unset)
  {
  	struct apply_state *state = opt->value;
  
  	BUG_ON_OPT_ARG(arg);
  
  	if (unset)
  		state->ws_ignore_action = ignore_ws_none;
  	else
  		state->ws_ignore_action = ignore_ws_change;
  	return 0;
  }
  
  static int apply_option_parse_whitespace(const struct option *opt,
  					 const char *arg, int unset)
  {
  	struct apply_state *state = opt->value;
  
  	BUG_ON_OPT_NEG(unset);
  
  	state->whitespace_option = arg;
  	if (parse_whitespace_option(state, arg))
  		return -1;
  	return 0;
  }
  
  static int apply_option_parse_directory(const struct option *opt,
  					const char *arg, int unset)
  {
  	struct apply_state *state = opt->value;
  
  	BUG_ON_OPT_NEG(unset);
  
  	strbuf_reset(&state->root);
  	strbuf_addstr(&state->root, arg);
  	strbuf_complete(&state->root, '/');
  	return 0;
  }
  
  int apply_all_patches(struct apply_state *state,
  		      int argc,
  		      const char **argv,
  		      int options)
  {
  	int i;
  	int res;
  	int errs = 0;
  	int read_stdin = 1;
  
  	for (i = 0; i < argc; i++) {
  		const char *arg = argv[i];
  		char *to_free = NULL;
  		int fd;
  
  		if (!strcmp(arg, "-")) {
  			res = apply_patch(state, 0, "<stdin>", options);
  			if (res < 0)
  				goto end;
  			errs |= res;
  			read_stdin = 0;
  			continue;
  		} else
  			arg = to_free = prefix_filename(state->prefix, arg);
  
  		fd = open(arg, O_RDONLY);
  		if (fd < 0) {
  			error(_("can't open patch '%s': %s"), arg, strerror(errno));
  			res = -128;
  			free(to_free);
  			goto end;
  		}
  		read_stdin = 0;
  		set_default_whitespace_mode(state);
  		res = apply_patch(state, fd, arg, options);
  		close(fd);
  		free(to_free);
  		if (res < 0)
  			goto end;
  		errs |= res;
  	}
  	set_default_whitespace_mode(state);
  	if (read_stdin) {
  		res = apply_patch(state, 0, "<stdin>", options);
  		if (res < 0)
  			goto end;
  		errs |= res;
  	}
  
  	if (state->whitespace_error) {
  		if (state->squelch_whitespace_errors &&
  		    state->squelch_whitespace_errors < state->whitespace_error) {
  			int squelched =
  				state->whitespace_error - state->squelch_whitespace_errors;
  			warning(Q_("squelched %d whitespace error",
  				   "squelched %d whitespace errors",
  				   squelched),
  				squelched);
  		}
  		if (state->ws_error_action == die_on_ws_error) {
  			error(Q_("%d line adds whitespace errors.",
  				 "%d lines add whitespace errors.",
  				 state->whitespace_error),
  			      state->whitespace_error);
  			res = -128;
  			goto end;
  		}
  		if (state->applied_after_fixing_ws && state->apply)
  			warning(Q_("%d line applied after"
  				   " fixing whitespace errors.",
  				   "%d lines applied after"
  				   " fixing whitespace errors.",
  				   state->applied_after_fixing_ws),
  				state->applied_after_fixing_ws);
  		else if (state->whitespace_error)
  			warning(Q_("%d line adds whitespace errors.",
  				   "%d lines add whitespace errors.",
  				   state->whitespace_error),
  				state->whitespace_error);
  	}
  
  	if (state->update_index) {
  		res = write_locked_index(state->repo->index, &state->lock_file, COMMIT_LOCK);
  		if (res) {
  			error(_("Unable to write new index file"));
  			res = -128;
  			goto end;
  		}
  	}
  
  	res = !!errs;
  
  end:
  	rollback_lock_file(&state->lock_file);
  
  	if (state->apply_verbosity <= verbosity_silent) {
  		set_error_routine(state->saved_error_routine);
  		set_warn_routine(state->saved_warn_routine);
  	}
  
  	if (res > -1)
  		return res;
  	return (res == -1 ? 1 : 128);
  }
  
  int apply_parse_options(int argc, const char **argv,
  			struct apply_state *state,
  			int *force_apply, int *options,
  			const char * const *apply_usage)
  {
  	struct option builtin_apply_options[] = {
  		{ OPTION_CALLBACK, 0, "exclude", state, N_("path"),
  			N_("don't apply changes matching the given path"),
  			PARSE_OPT_NONEG, apply_option_parse_exclude },
  		{ OPTION_CALLBACK, 0, "include", state, N_("path"),
  			N_("apply changes matching the given path"),
  			PARSE_OPT_NONEG, apply_option_parse_include },
  		{ OPTION_CALLBACK, 'p', NULL, state, N_("num"),
  			N_("remove <num> leading slashes from traditional diff paths"),
  			0, apply_option_parse_p },
  		OPT_BOOL(0, "no-add", &state->no_add,
  			N_("ignore additions made by the patch")),
  		OPT_BOOL(0, "stat", &state->diffstat,
  			N_("instead of applying the patch, output diffstat for the input")),
  		OPT_NOOP_NOARG(0, "allow-binary-replacement"),
  		OPT_NOOP_NOARG(0, "binary"),
  		OPT_BOOL(0, "numstat", &state->numstat,
  			N_("show number of added and deleted lines in decimal notation")),
  		OPT_BOOL(0, "summary", &state->summary,
  			N_("instead of applying the patch, output a summary for the input")),
  		OPT_BOOL(0, "check", &state->check,
  			N_("instead of applying the patch, see if the patch is applicable")),
  		OPT_BOOL(0, "index", &state->check_index,
  			N_("make sure the patch is applicable to the current index")),
  		OPT_BOOL('N', "intent-to-add", &state->ita_only,
  			N_("mark new files with `git add --intent-to-add`")),
  		OPT_BOOL(0, "cached", &state->cached,
  			N_("apply a patch without touching the working tree")),
  		OPT_BOOL_F(0, "unsafe-paths", &state->unsafe_paths,
  			   N_("accept a patch that touches outside the working area"),
  			   PARSE_OPT_NOCOMPLETE),
  		OPT_BOOL(0, "apply", force_apply,
  			N_("also apply the patch (use with --stat/--summary/--check)")),
  		OPT_BOOL('3', "3way", &state->threeway,
  			 N_( "attempt three-way merge if a patch does not apply")),
  		OPT_FILENAME(0, "build-fake-ancestor", &state->fake_ancestor,
  			N_("build a temporary index based on embedded index information")),
  		/* Think twice before adding "--nul" synonym to this */
  		OPT_SET_INT('z', NULL, &state->line_termination,
  			N_("paths are separated with NUL character"), '\0'),
  		OPT_INTEGER('C', NULL, &state->p_context,
  				N_("ensure at least <n> lines of context match")),
  		{ OPTION_CALLBACK, 0, "whitespace", state, N_("action"),
  			N_("detect new or modified lines that have whitespace errors"),
  			0, apply_option_parse_whitespace },
  		{ OPTION_CALLBACK, 0, "ignore-space-change", state, NULL,
  			N_("ignore changes in whitespace when finding context"),
  			PARSE_OPT_NOARG, apply_option_parse_space_change },
  		{ OPTION_CALLBACK, 0, "ignore-whitespace", state, NULL,
  			N_("ignore changes in whitespace when finding context"),
  			PARSE_OPT_NOARG, apply_option_parse_space_change },
  		OPT_BOOL('R', "reverse", &state->apply_in_reverse,
  			N_("apply the patch in reverse")),
  		OPT_BOOL(0, "unidiff-zero", &state->unidiff_zero,
  			N_("don't expect at least one line of context")),
  		OPT_BOOL(0, "reject", &state->apply_with_reject,
  			N_("leave the rejected hunks in corresponding *.rej files")),
  		OPT_BOOL(0, "allow-overlap", &state->allow_overlap,
  			N_("allow overlapping hunks")),
  		OPT__VERBOSE(&state->apply_verbosity, N_("be verbose")),
  		OPT_BIT(0, "inaccurate-eof", options,
  			N_("tolerate incorrectly detected missing new-line at the end of file"),
  			APPLY_OPT_INACCURATE_EOF),
  		OPT_BIT(0, "recount", options,
  			N_("do not trust the line counts in the hunk headers"),
  			APPLY_OPT_RECOUNT),
  		{ OPTION_CALLBACK, 0, "directory", state, N_("root"),
  			N_("prepend <root> to all filenames"),
  			0, apply_option_parse_directory },
  		OPT_END()
  	};
  
  	return parse_options(argc, argv, state->prefix, builtin_apply_options, apply_usage, 0);
  }
  